test: catch backtick and bracket-quoted table names in self-scan

- UPDATE pattern alternative corrected (UPDATE ... children, not
  UPDATE SET)
- allowlist comparison uses as_posix() so Windows separators cannot
  make the DAO itself appear as an offender

custom_components/nestquest/__init__.py

@@ -11,7 +11,7 @@ from homeassistant.core import HomeAssistant
 
 from .const import DOMAIN, LOGGER
 from .db import NestQuestDatabase
-from .schema import SCHEMA_V1_STATEMENTS, async_apply_ddl
+from .migrations import apply_migrations
 from .store import async_get_db_path
 
 _LOGGER = LOGGER
@@ -52,7 +52,7 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
 
     database = await NestQuestDatabase(hass).open(await async_get_db_path(hass))
     try:
-        await async_apply_ddl(database, SCHEMA_V1_STATEMENTS)
+        await apply_migrations(database)
         remove_update_listener = entry.add_update_listener(_async_update_listener)
     except BaseException:
         await database.close()

custom_components/nestquest/dao_children.py

@@ -0,0 +1,289 @@
+"""Typed DAO layer for the children and admin_users tables.
+
+All SQL for ``children`` and ``admin_users`` lives in this module per
+the feature guardrail: callers get typed dataclasses back and never see
+raw rows or SQL.  Every method is async and runs through
+:class:`~.db.NestQuestDatabase`, so each statement executes on the HA
+executor and the event loop never blocks.
+
+Error contract: violations surface as the underlying
+:class:`sqlite3.IntegrityError` (duplicate, foreign-key, or CHECK
+failure) from the execute call; the DAO adds no wrapping exception
+type.  A get that matches nothing returns ``None``; a mutation that
+matches nothing is reported by :class:`~.db.ExecutionResult.rowcount`,
+which each method returns where the caller may need it (reorder, and
+the admin remove/set paths).
+"""
+from __future__ import annotations
+
+import asyncio
+from dataclasses import dataclass
+
+from .db import NestQuestDatabase
+
+
+@dataclass(frozen=True)
+class ChildRecord:
+    """One row of ``children``."""
+
+    id: int
+    display_name: str
+    colour: str | None
+    avatar_ref: str | None
+    sort_order: int
+    is_active: bool
+    created_at: str
+
+
+@dataclass(frozen=True)
+class AdminUserRecord:
+    """One row of ``admin_users``."""
+
+    ha_user_id: str
+    added_at: str
+
+
+def _child_from_row(row: tuple) -> ChildRecord:
+    """Build a :class:`ChildRecord` from a SELECT row."""
+    return ChildRecord(
+        id=row[0],
+        display_name=row[1],
+        colour=row[2],
+        avatar_ref=row[3],
+        sort_order=row[4],
+        is_active=bool(row[5]),
+        created_at=row[6],
+    )
+
+
+_CHILD_COLUMNS = (
+    "id, display_name, colour, avatar_ref, sort_order, is_active, created_at"
+)
+
+
+#: One asyncio.Lock per (connection wrapper, running loop), shared by
+#: every ChildrenDao instance over the same database: the wrapper
+#: rejects a second concurrent transaction with RuntimeError, so ALL
+#: transactional DAO operations on one connection must queue here, not
+#: per-instance.  Keyed like the migration runner's lock; entries are
+#: never evicted (a config entry holds one wrapper per process).
+_CONNECTION_LOCKS: dict[tuple[int, int], asyncio.Lock] = {}
+
+
+def _connection_lock(database) -> asyncio.Lock:
+    """Return the shared transaction-serializing lock for ``database``."""
+    loop = asyncio.get_running_loop()
+    key = (id(database), id(loop))
+    lock = _CONNECTION_LOCKS.get(key)
+    if lock is None:
+        lock = asyncio.Lock()
+        _CONNECTION_LOCKS[key] = lock
+    return lock
+
+
+class ChildrenDao:
+    """Typed async data access for the ``children`` table.
+
+    Deletion is deliberately absent: children are deactivated, never
+    deleted, because completion history references them (feature
+    guardrail).
+    """
+
+    def __init__(self, database) -> None:
+        self._database = database
+
+    async def create(
+        self,
+        display_name: str,
+        created_at: str,
+        *,
+        colour: str | None = None,
+        avatar_ref: str | None = None,
+        sort_order: int = 0,
+        is_active: bool = True,
+    ) -> ChildRecord:
+        """Insert one child and return the record as stored."""
+        result = await self._database.execute(
+            "INSERT INTO children (display_name, colour, avatar_ref, "
+            "sort_order, is_active, created_at) VALUES (?, ?, ?, ?, ?, ?)",
+            (
+                display_name,
+                colour,
+                avatar_ref,
+                sort_order,
+                int(is_active),
+                created_at,
+            ),
+        )
+        child = await self.get(result.lastrowid)
+        assert child is not None
+        return child
+
+    async def get(self, child_id: int) -> ChildRecord | None:
+        """Return the child with ``child_id``, or None."""
+        row = await self._database.fetch_one(
+            f"SELECT {_CHILD_COLUMNS} FROM children WHERE id = ?",
+            (child_id,),
+        )
+        return _child_from_row(row) if row is not None else None
+
+    async def list_active(self) -> list[ChildRecord]:
+        """Return active children ordered by sort_order, then id."""
+        rows = await self._database.fetch_all(
+            f"SELECT {_CHILD_COLUMNS} FROM children WHERE is_active = 1 "
+            "ORDER BY sort_order, id"
+        )
+        return [_child_from_row(row) for row in rows]
+
+    async def list_all(self) -> list[ChildRecord]:
+        """Return all children ordered by sort_order, then id."""
+        rows = await self._database.fetch_all(
+            f"SELECT {_CHILD_COLUMNS} FROM children "
+            "ORDER BY sort_order, id"
+        )
+        return [record for record in map(_child_from_row, rows)]
+
+    async def update(
+        self,
+        child_id: int,
+        *,
+        display_name: str | None = None,
+        colour: str | None = None,
+        avatar_ref: str | None = None,
+        sort_order: int | None = None,
+    ) -> int:
+        """Update the given fields; returns rows updated (0 if absent).
+
+        Only non-None arguments are written, so a caller cannot
+        accidentally blank a column by omitting it.
+        """
+        assignments: list[str] = []
+        parameters: list[object] = []
+        if display_name is not None:
+            assignments.append("display_name = ?")
+            parameters.append(display_name)
+        if colour is not None:
+            assignments.append("colour = ?")
+            parameters.append(colour)
+        if avatar_ref is not None:
+            assignments.append("avatar_ref = ?")
+            parameters.append(avatar_ref)
+        if sort_order is not None:
+            assignments.append("sort_order = ?")
+            parameters.append(sort_order)
+        if not assignments:
+            return 0
+        parameters.append(child_id)
+        result = await self._database.execute(
+            f"UPDATE children SET {', '.join(assignments)} WHERE id = ?",
+            tuple(parameters),
+        )
+        return result.rowcount
+
+    async def set_active(self, child_id: int, is_active: bool) -> int:
+        """Set the child's active flag; returns rows updated (0 if absent)."""
+        result = await self._database.execute(
+            "UPDATE children SET is_active = ? WHERE id = ?",
+            (int(is_active), child_id),
+        )
+        return result.rowcount
+
+    async def reorder(self, ordered_ids: list[int]) -> None:
+        """Persist a new sort order: ``ordered_ids[i]`` gets sort_order i.
+
+        Runs inside one transaction; positions are staged at offset
+        -len (all negative, so any permutation of the same ids never
+        collides mid-reorder under the wrapper's single-connection
+        serialization), then finalized 0..n-1.  Duplicate ids are
+        rejected up front: they cannot all hold distinct positions, and
+        silently assigning the last occurrence's index would hide a
+        caller bug.
+
+        Concurrent reorder() calls on one connection are serialized by
+        a connection-scoped asyncio lock (shared across every ChildrenDao
+        over the same wrapper, however many instances): the wrapper's
+        transaction() rejects a second concurrent transaction with
+        RuntimeError, so racing callers would crash instead of
+        queueing.  The lock makes the second call wait, then run
+        against the first call's final state.
+        """
+        if not ordered_ids:
+            return
+        if len(set(ordered_ids)) != len(ordered_ids):
+            raise ValueError(
+                "reorder() received duplicate child ids; every id must "
+                "appear at most once"
+            )
+        async with _connection_lock(self._database):
+            async with self._database.transaction():
+                offset = len(ordered_ids)
+                await self._database.execute_many(
+                    "UPDATE children SET sort_order = ? WHERE id = ?",
+                    [
+                        (-(offset + index), child_id)
+                        for index, child_id in enumerate(ordered_ids)
+                    ],
+                )
+                await self._database.execute_many(
+                    "UPDATE children SET sort_order = ? WHERE id = ?",
+                    [
+                        (index, child_id)
+                        for index, child_id in enumerate(ordered_ids)
+                    ],
+                )
+
+
+class AdminUsersDao:
+    """Typed async access to the ``admin_users`` allowlist.
+
+    The allowlist stores HA user IDs, never usernames (feature
+    guardrail); an empty allowlist means no admin, enforced by callers
+    resolving through :meth:`exists`.
+    """
+
+    def __init__(self, database) -> None:
+        self._database = database
+
+    async def add(self, ha_user_id: str, added_at: str) -> bool:
+        """Add a user to the allowlist; True if inserted, False if present.
+
+        Idempotent under concurrency: a single INSERT ... ON CONFLICT DO
+        NOTHING decides and inserts in one statement (the wrapper
+        serializes statements, not check-then-insert sequences, so a
+        SELECT/INSERT pair would let two concurrent adds both see no
+        row and the second one raise IntegrityError).  rowcount reports
+        whether the insert actually happened.
+        """
+        result = await self._database.execute(
+            "INSERT INTO admin_users (ha_user_id, added_at) VALUES (?, ?) "
+            "ON CONFLICT (ha_user_id) DO NOTHING",
+            (ha_user_id, added_at),
+        )
+        return result.rowcount > 0
+
+    async def remove(self, ha_user_id: str) -> bool:
+        """Remove a user from the allowlist; True if a row was removed."""
+        result = await self._database.execute(
+            "DELETE FROM admin_users WHERE ha_user_id = ?",
+            (ha_user_id,),
+        )
+        return result.rowcount > 0
+
+    async def list(self) -> list[AdminUserRecord]:
+        """Return every allowlisted user, oldest first."""
+        rows = await self._database.fetch_all(
+            "SELECT ha_user_id, added_at FROM admin_users "
+            "ORDER BY added_at, ha_user_id"
+        )
+        return [
+            AdminUserRecord(ha_user_id=row[0], added_at=row[1])
+            for row in rows
+        ]
+
+    async def exists(self, ha_user_id: str) -> bool:
+        """Return True if ``ha_user_id`` is allowlisted."""
+        row = await self._database.fetch_one(
+            "SELECT 1 FROM admin_users WHERE ha_user_id = ?",
+            (ha_user_id,),
+        )
+        return row is not None

custom_components/nestquest/migrations.py

@@ -0,0 +1,236 @@
+"""Versioned schema migration runner for the NestQuest SQLite database.
+
+The runner owns one metadata table, ``nestquest_schema_version``, holding
+a single row with the schema version the database file currently
+reflects.  Migrations are declared as an ordered list: entry ``n``
+upgrades version ``n-1`` to version ``n``.  Applying a migration means
+running its DDL inside one transaction and stamping the new version in
+that same transaction, so a database never persists a half-applied
+migration: any failure rolls the statements and the version stamp back
+together, leaving the file at its prior version.
+
+Version 0 means "the file exists but carries no NestQuest schema yet"
+— a fresh file, or a file this integration has never written.  Starting
+the runner against version 0 applies migration 1, which applies the
+full v1 DDL from :mod:`.schema` and stamps version 1.
+
+Each migration's statements and its version stamp run inside ONE
+transaction, and the stamp is written as DELETE + INSERT rather than
+UPDATE because a version-0 database has no version row to update yet.
+An UPDATE form would silently match zero rows there and leave the
+database migrated but unstamped — reporting version 0 forever, and
+re-applying migration 1 on every startup.  The DELETE+INSERT shape is
+also what makes the stamp a replace, so the row never duplicates.
+
+Idempotence across restarts: a database already at the latest version
+has no pending migrations, so the runner opens a read-only check, finds
+nothing to do, and leaves the file byte-untouched (no write transaction
+is opened, so no WAL churn).
+
+Migration list policy: entries are append-only.  Once shipped, a
+migration's SQL must never be edited — an old database applying it for
+the first time and a fresh database would then diverge.  Fix-forward
+with a new migration instead.  The version stamp lives in the same
+SQLite file as the data it describes, so restoring a backup restores
+its matching schema version with it.
+
+Corrupt or missing files are not this module's concern: startup
+handling of those cases is task d5bca74b, which decides whether to
+open fresh or raise ConfigEntryNotReady.  This runner assumes it is
+handed an open, working connection.
+"""
+from __future__ import annotations
+
+import asyncio
+import logging
+from collections.abc import Sequence
+
+from .db import NestQuestDatabase
+from .schema import SCHEMA_V1_STATEMENTS
+
+LOGGER = logging.getLogger(__name__)
+
+#: Metadata table holding the applied schema version.  Prefixed with the
+#: integration domain so a config directory shared with other tools can
+#: never collide with a foreign ``schema_version`` table.
+VERSION_TABLE = "nestquest_schema_version"
+
+#: DDL for the version metadata table.  The singleton-row invariant is
+#: enforced by the schema itself: ``id`` is fixed at 1 by CHECK, keyed
+#: PRIMARY KEY, so the table can never hold a second row, and the
+#: stamp write is an UPDATE (no DELETE+INSERT needed).  ``version`` is
+#: a positive integer: version 0 means "no row" and is never stored,
+#: so a negative or zero stored value is corruption, not a state the
+#: runner can act on.
+VERSION_TABLE_DDL = f"""
+    CREATE TABLE IF NOT EXISTS {VERSION_TABLE} (
+        id INTEGER NOT NULL PRIMARY KEY CHECK (id = 1),
+        version INTEGER NOT NULL CHECK (version >= 1)
+    )
+"""
+
+#: One-based index into :data:`MIGRATIONS`: entry ``n`` upgrades
+#: version ``n-1`` to version ``n``.
+MIGRATION_1_V1_DDL: list[str] = list(SCHEMA_V1_STATEMENTS)
+
+#: The ordered migration list.  Append-only: never edit an applied
+#: entry, add the next one instead.
+MIGRATIONS: Sequence[Sequence[str]] = [
+    MIGRATION_1_V1_DDL,
+]
+
+
+async def _create_version_table(database: NestQuestDatabase) -> None:
+    """Create the version metadata table if it does not exist.
+
+    The table is created before any version check: it is the runner's
+    own bookkeeping, and creating it is idempotent.  The DDL enforces
+    the singleton-row invariant (``id`` fixed at 1) and a positive
+    integer version at the database level.
+    """
+    await database.execute(VERSION_TABLE_DDL)
+
+
+async def read_schema_version(database: NestQuestDatabase) -> int:
+    """Return the schema version recorded in the database.
+
+    Returns 0 when the version table or its row is missing — the
+    "fresh file" case.  A stored version higher than the runner knows
+    is surfaced as-is; the caller decides how to treat a future version.
+
+    Reading is deliberately passive: a missing table raises, it is not
+    swallowed into 0, because :func:`apply_migrations` always creates
+    the table before reading and a direct reader hitting "no such
+    table" is a caller bug worth surfacing, not a fresh file.
+    """
+    row = await database.fetch_one(
+        f"SELECT version FROM {VERSION_TABLE} LIMIT 1"
+    )
+    if row is None:
+        return 0
+    version = row[0]
+    if not isinstance(version, int) or isinstance(version, bool):
+        raise RuntimeError(
+            f"Schema version metadata is not an integer: {version!r}"
+        )
+    if version < 1:
+        raise RuntimeError(
+            f"Schema version metadata is invalid (must be >= 1): {version!r}"
+        )
+    return version
+
+
+#: One asyncio.Lock per connection wrapper, created lazily and bound to
+#: the running loop, serializing whole apply_migrations runs so two
+#: concurrent callers on one connection queue instead of colliding on
+#: the wrapper's single-transaction rule.
+_MIGRATION_LOCKS: dict[int, asyncio.Lock] = {}
+
+
+def _migration_lock(database: NestQuestDatabase) -> asyncio.Lock:
+    """Return the migration lock bound to ``database``'s running loop."""
+    loop = asyncio.get_running_loop()
+    key = (id(database), id(loop))
+    lock = _MIGRATION_LOCKS.get(key)
+    if lock is None:
+        lock = asyncio.Lock()
+        _MIGRATION_LOCKS[key] = lock
+    return lock
+
+
+async def apply_migrations(
+    database: NestQuestDatabase,
+    migrations: Sequence[Sequence[str]] = MIGRATIONS,
+) -> int:
+    """Bring the database schema up to the latest version.
+
+    Reads the current version, applies every pending migration in order
+    — each inside one transaction that also stamps the new version —
+    and returns the resulting version.  Applying zero pending
+    migrations (database already current) is a no-op that logs at debug
+    level and opens no write transaction.
+
+    The version is re-read inside each migration transaction before
+    deciding to apply it: the outer read is advisory only (loop bounds,
+    no-op fast path), and on one shared connection two interleaved
+    runners would otherwise both read the same version and both apply
+    a non-idempotent migration.  Under the transaction's lock the
+    second runner sees the first runner's stamp and skips.
+
+    Runners on one connection are serialized by an asyncio lock held
+    for the whole decide-and-apply span: NestQuestDatabase rejects a
+    second transaction while one is active (RuntimeError), so
+    concurrent callers must queue, and the lock makes that queueing
+    explicit.  The loser of the race re-reads the version once it
+    acquires the lock, sees the winner's stamp, and applies nothing.
+
+    Raises whatever the failing migration raised, with the database
+    rolled back to its prior version and prior rows untouched.
+    """
+    async with _migration_lock(database):
+        await _create_version_table(database)
+        current = await read_schema_version(database)
+        latest = len(migrations)
+
+        if current > latest:
+            raise RuntimeError(
+                f"Database schema version {current} is newer than this "
+                f"integration understands (latest known: {latest}); "
+                "downgrades are not supported"
+            )
+
+        if current == latest:
+            LOGGER.debug(
+                "NestQuest schema already at version %d; "
+                "no migrations to apply",
+                current,
+            )
+            return current
+
+        for target in range(current + 1, latest + 1):
+            applied = False
+            async with database.transaction():
+                # Re-read the version INSIDE the write transaction: the
+                # outer read was advisory, and the wrapper serializes
+                # individual statements, not the read-decide-apply
+                # decision.  Under the transaction's lock the version
+                # cannot change between the read and the stamp, and the
+                # loser of an interleaved race (a queued second caller
+                # re-running apply_migrations after the winner already
+                # migrated) re-reads here, sees the winner's stamp, and
+                # skips instead of re-applying a non-idempotent
+                # migration with a stale version.
+                in_tx_version = await read_schema_version(database)
+                if in_tx_version > latest:
+                    raise RuntimeError(
+                        f"Database schema version {in_tx_version} is newer "
+                        f"than this integration understands (latest known: "
+                        f"{latest}); downgrades are not supported"
+                    )
+                if in_tx_version < target:
+                    for sql in migrations[target - 1]:
+                        await database.execute(sql)
+                    # INSERT keyed on the singleton row (id = 1): a
+                    # fresh file has no row yet, and migration 1 is the
+                    # only migration a version-0 database can run, so
+                    # the row is seeded by the same statement batch
+                    # when needed.  UPDATE alone would silently match
+                    # zero rows there.
+                    await database.execute(
+                        f"INSERT INTO {VERSION_TABLE} (id, version) "
+                        "VALUES (1, ?) "
+                        "ON CONFLICT (id) DO UPDATE SET version = "
+                        "excluded.version",
+                        (target,),
+                    )
+                    applied = True
+            if applied:
+                LOGGER.info(
+                    "NestQuest schema migrated to version %d "
+                    "(%d statement%s)",
+                    target,
+                    len(migrations[target - 1]),
+                    "s" if len(migrations[target - 1]) != 1 else "",
+                )
+
+        return latest

tests/test_dao_children.py

@@ -0,0 +1,553 @@
+"""Tests for dao_children.py: typed DAO for children and admin_users."""
+from __future__ import annotations
+
+import asyncio
+import sqlite3
+
+import pytest
+
+from custom_components.nestquest.dao_children import (
+    AdminUserRecord,
+    AdminUsersDao,
+    ChildRecord,
+    ChildrenDao,
+)
+from custom_components.nestquest.db import NestQuestDatabase
+from custom_components.nestquest.schema import SCHEMA_V1_STATEMENTS
+from custom_components.nestquest.migrations import apply_migrations
+
+
+def _run(coro):
+    return asyncio.new_event_loop().run_until_complete(coro)
+
+
+def _make_hass_mock():
+    from unittest.mock import AsyncMock, MagicMock
+
+    hass = MagicMock()
+    hass.async_add_executor_job = AsyncMock(side_effect=(lambda fn, *a: fn(*a)))
+    return hass
+
+
+def _open_db(path) -> NestQuestDatabase:
+    database = NestQuestDatabase(_make_hass_mock())
+    _run(database.open(path))
+    _run(apply_migrations(database))
+    return database
+
+
+def _daos(database) -> tuple[ChildrenDao, AdminUsersDao]:
+    return ChildrenDao(database), AdminUsersDao(database)
+
+
+NOW = "2026-09-14T11:00:00+00:00"
+
+
+def _make_child(dao, name="Ada", **kwargs) -> ChildRecord:
+    return _run(dao.create(name, NOW, **kwargs))
+
+
+# ---------------------------------------------------------------------------
+# children: create and get
+# ---------------------------------------------------------------------------
+
+
+def test_create_returns_typed_record(tmp_path) -> None:
+    database = _open_db(tmp_path / "create.db")
+    try:
+        dao, _ = _daos(database)
+        child = _make_child(dao, colour="#ff0000", avatar_ref="avatars/1")
+        assert isinstance(child, ChildRecord)
+        assert child.id == 1
+        assert child.display_name == "Ada"
+        assert child.colour == "#ff0000"
+        assert child.avatar_ref == "avatars/1"
+        assert child.sort_order == 0
+        assert child.is_active is True
+        assert child.created_at == NOW
+    finally:
+        _run(database.close())
+
+
+def test_get_returns_none_for_missing_child(tmp_path) -> None:
+    database = _open_db(tmp_path / "get-missing.db")
+    try:
+        dao, _ = _daos(database)
+        assert _run(dao.get(999)) is None
+    finally:
+        _run(database.close())
+
+
+def test_create_duplicate_name_is_allowed(tmp_path) -> None:
+    database = _open_db(tmp_path / "dup-name.db")
+    try:
+        dao, _ = _daos(database)
+        first = _make_child(dao, "Ada")
+        second = _make_child(dao, "Ada")
+        assert first.id != second.id
+    finally:
+        _run(database.close())
+
+
+# ---------------------------------------------------------------------------
+# children: list active / list all
+# ---------------------------------------------------------------------------
+
+
+def test_list_active_excludes_inactive_and_sorts(tmp_path) -> None:
+    database = _open_db(tmp_path / "list-active.db")
+    try:
+        dao, _ = _daos(database)
+        _make_child(dao, "Bo", sort_order=2)
+        ada = _make_child(dao, "Ada", sort_order=1)
+        cy = _make_child(dao, "Cy", sort_order=1)
+        _make_child(dao, "Dee", sort_order=0)
+        _run(dao.set_active(ada.id, False))
+        active = _run(dao.list_active())
+        assert [c.display_name for c in active] == ["Dee", "Cy", "Bo"]
+        assert all(c.is_active for c in active)
+    finally:
+        _run(database.close())
+
+
+def test_list_all_includes_inactive(tmp_path) -> None:
+    database = _open_db(tmp_path / "list-all.db")
+    try:
+        dao, _ = _daos(database)
+        ada = _make_child(dao, "Ada", sort_order=1)
+        _make_child(dao, "Bo", sort_order=0)
+        _run(dao.set_active(ada.id, False))
+        all_children = _run(dao.list_all())
+        assert [c.display_name for c in all_children] == ["Bo", "Ada"]
+        assert all_children[1].is_active is False
+    finally:
+        _run(database.close())
+
+
+# ---------------------------------------------------------------------------
+# children: update, set_active, reorder
+# ---------------------------------------------------------------------------
+
+
+def test_update_fields_round_trip(tmp_path) -> None:
+    database = _open_db(tmp_path / "update.db")
+    try:
+        dao, _ = _daos(database)
+        child = _make_child(dao, "Ada", colour="#111111")
+        updated = _run(
+            dao.update(
+                child.id,
+                display_name="Ada L.",
+                colour="#222222",
+                avatar_ref="avatars/x.png",
+            )
+        )
+        assert updated == 1
+        fetched = _run(dao.get(child.id))
+        assert fetched is not None
+        assert fetched.display_name == "Ada L."
+        assert fetched.colour == "#222222"
+        assert fetched.avatar_ref == "avatars/x.png"
+        assert fetched.sort_order == 0
+    finally:
+        _run(database.close())
+
+
+def test_update_omitted_fields_untouched(tmp_path) -> None:
+    database = _open_db(tmp_path / "update-partial.db")
+    try:
+        dao, _ = _daos(database)
+        child = _make_child(dao, "Ada", colour="#111111")
+        _run(dao.update(child.id, display_name="Ada L."))
+        fetched = _run(dao.get(child.id))
+        assert fetched.colour == "#111111"
+    finally:
+        _run(database.close())
+
+
+def test_update_no_fields_returns_zero_and_changes_nothing(tmp_path) -> None:
+    database = _open_db(tmp_path / "update-empty.db")
+    try:
+        dao, _ = _daos(database)
+        child = _make_child(dao, "Ada")
+        assert _run(dao.update(child.id)) == 0
+        fetched = _run(dao.get(child.id))
+        assert fetched is not None and fetched.display_name == "Ada"
+    finally:
+        _run(database.close())
+
+
+def test_update_missing_child_returns_zero(tmp_path) -> None:
+    database = _open_db(tmp_path / "update-missing.db")
+    try:
+        dao, _ = _daos(database)
+        assert _run(dao.update(999, display_name="X")) == 0
+    finally:
+        _run(database.close())
+
+
+def test_set_active_missing_child_returns_zero(tmp_path) -> None:
+    database = _open_db(tmp_path / "set-active-missing.db")
+    try:
+        dao, _ = _daos(database)
+        assert _run(dao.set_active(999, False)) == 0
+    finally:
+        _run(database.close())
+
+
+def test_reorder_assigns_positions_in_order(tmp_path) -> None:
+    database = _open_db(tmp_path / "reorder.db")
+    try:
+        dao, _ = _daos(database)
+        a = _make_child(dao, "Ada")
+        b = _make_child(dao, "Bo")
+        c = _make_child(dao, "Cy")
+        _run(dao.reorder([c.id, a.id, b.id]))
+        children = _run(dao.list_all())
+        assert [x.display_name for x in children] == ["Cy", "Ada", "Bo"]
+        assert [x.sort_order for x in children] == [0, 1, 2]
+    finally:
+        _run(database.close())
+
+
+def test_reorder_is_transactional_and_idempotent(tmp_path) -> None:
+    database = _open_db(tmp_path / "reorder-idempotent.db")
+    try:
+        dao, _ = _daos(database)
+        a = _make_child(dao, "Ada")
+        b = _make_child(dao, "Bo")
+        _run(dao.reorder([b.id, a.id]))
+        _run(dao.reorder([b.id, a.id]))
+        children = _run(dao.list_all())
+        assert [(x.display_name, x.sort_order) for x in children] == [
+            ("Bo", 0),
+            ("Ada", 1),
+        ]
+    finally:
+        _run(database.close())
+
+
+def test_reorder_empty_list_is_noop(tmp_path) -> None:
+    database = _open_db(tmp_path / "reorder-empty.db")
+    try:
+        dao, _ = _daos(database)
+        _make_child(dao, "Ada")
+        _run(dao.reorder([]))
+        children = _run(dao.list_all())
+        assert children[0].sort_order == 0
+    finally:
+        _run(database.close())
+
+
+def test_reorder_unknown_id_leaves_it_untouched(tmp_path) -> None:
+    database = _open_db(tmp_path / "reorder-unknown.db")
+    try:
+        dao, _ = _daos(database)
+        a = _make_child(dao, "Ada")
+        _run(dao.reorder([a.id, 999]))
+        children = _run(dao.list_all())
+        assert children[0].sort_order == 0
+    finally:
+        _run(database.close())
+
+
+def test_reorder_rolls_back_to_original_order_on_failure(tmp_path) -> None:
+    """A failing finalize batch rolls the whole reorder back.
+
+    The two-phase staging is only meaningful if a crash between the
+    batches leaves the original order intact: monkeypatch execute_many
+    so the finalize (non-negative) batch raises, then assert every
+    sort_order is unchanged.
+    """
+    database = _open_db(tmp_path / "reorder-rollback.db")
+    try:
+        dao, _ = _daos(database)
+        a = _make_child(dao, "Ada", sort_order=0)
+        b = _make_child(dao, "Bo", sort_order=1)
+
+        original_execute_many = database.execute_many
+
+        async def _failing_execute_many(sql, parameters):
+            # The staging batch writes negative positions; the finalize
+            # batch writes 0..n-1.  Fail the finalize batch.
+            if all(position >= 0 for position, _ in parameters):
+                raise sqlite3.OperationalError("boom")
+            return await original_execute_many(sql, parameters)
+
+        database.execute_many = _failing_execute_many
+        with pytest.raises(sqlite3.OperationalError, match="boom"):
+            _run(dao.reorder([b.id, a.id]))
+        children = _run(dao.list_all())
+        assert [(c.display_name, c.sort_order) for c in children] == [
+            ("Ada", 0),
+            ("Bo", 1),
+        ], "failed reorder must leave original sort orders intact"
+    finally:
+        _run(database.close())
+
+
+def test_reorder_rejects_duplicate_ids(tmp_path) -> None:
+    database = _open_db(tmp_path / "reorder-duplicate.db")
+    try:
+        dao, _ = _daos(database)
+        a = _make_child(dao, "Ada")
+        with pytest.raises(ValueError, match="duplicate"):
+            _run(dao.reorder([a.id, a.id]))
+        fetched = _run(dao.get(a.id))
+        assert fetched is not None and fetched.sort_order == 0
+    finally:
+        _run(database.close())
+
+
+def test_reorder_concurrent_calls_serialize(tmp_path) -> None:
+    """Concurrent reorders from DIFFERENT DAO instances queue safely.
+
+    Two ChildrenDao objects over one connection race two reorders: the
+    connection-scoped lock makes the second wait, then run against the
+    first call's final state.  Without the lock the wrapper's
+    transaction() would reject the second concurrent transaction with
+    RuntimeError.
+    """
+    async def _main() -> None:
+        database = NestQuestDatabase(_make_hass_mock())
+        await database.open(tmp_path / "reorder-concurrent.db")
+        try:
+            await apply_migrations(database)
+            dao_a, _ = _daos(database)
+            a = await dao_a.create("Ada", NOW)
+            b = await dao_a.create("Bo", NOW)
+            dao_b, _ = _daos(database)  # second instance, same connection
+            task_1 = asyncio.ensure_future(dao_a.reorder([b.id, a.id]))
+            await asyncio.sleep(0)
+            task_2 = asyncio.ensure_future(dao_b.reorder([a.id, b.id]))
+            await asyncio.gather(task_1, task_2)
+            children = await dao_a.list_all()
+            orders = {c.display_name: c.sort_order for c in children}
+            assert sorted(orders.values()) == [0, 1]
+        finally:
+            await database.close()
+
+    _run(_main())
+
+
+# ---------------------------------------------------------------------------
+# admin_users: add, remove, list, exists
+# ---------------------------------------------------------------------------
+
+
+def test_admin_add_then_exists(tmp_path) -> None:
+    database = _open_db(tmp_path / "admin-add.db")
+    try:
+        _, dao = _daos(database)
+        assert _run(dao.add("user-1", NOW)) is True
+        assert _run(dao.exists("user-1")) is True
+        assert _run(dao.exists("user-2")) is False
+    finally:
+        _run(database.close())
+
+
+def test_admin_add_is_idempotent(tmp_path) -> None:
+    database = _open_db(tmp_path / "admin-idempotent.db")
+    try:
+        _, dao = _daos(database)
+        assert _run(dao.add("user-1", NOW)) is True
+        assert _run(dao.add("user-1", NOW)) is False
+        records = _run(dao.list())
+        assert len(records) == 1
+        assert records[0].added_at == NOW
+    finally:
+        _run(database.close())
+
+
+def test_admin_add_concurrent_calls_are_idempotent(tmp_path) -> None:
+    """Concurrent add() calls of the same user: one inserts, rest False.
+
+    The single-statement ON CONFLICT DO NOTHING makes the decision and
+    the write atomic per statement, so racing coroutines cannot both
+    'see no row' and one of them raise IntegrityError.
+    """
+    async def _main() -> None:
+        database = NestQuestDatabase(_make_hass_mock())
+        await database.open(tmp_path / "admin-race.db")
+        try:
+            await apply_migrations(database)
+            _, dao = _daos(database)
+            tasks = [
+                asyncio.ensure_future(dao.add("user-1", NOW))
+                for _ in range(5)
+            ]
+            await asyncio.sleep(0)
+            results = list(await asyncio.gather(*tasks))
+            assert sorted(results) == [False, False, False, False, True]
+            records = await dao.list()
+            assert len(records) == 1
+            assert records[0].added_at == NOW
+        finally:
+            await database.close()
+
+    _run(_main())
+
+
+def test_admin_add_preserves_original_added_at(tmp_path) -> None:
+    database = _open_db(tmp_path / "admin-added-at.db")
+    try:
+        _, dao = _daos(database)
+        _run(dao.add("user-1", NOW))
+        _run(dao.add("user-1", "2026-09-15T00:00:00+00:00"))
+        records = _run(dao.list())
+        assert records[0].added_at == NOW
+    finally:
+        _run(database.close())
+
+
+def test_admin_remove_returns_true_then_false(tmp_path) -> None:
+    database = _open_db(tmp_path / "admin-remove.db")
+    try:
+        _, dao = _daos(database)
+        _run(dao.add("user-1", NOW))
+        assert _run(dao.remove("user-1")) is True
+        assert _run(dao.remove("user-1")) is False
+        assert _run(dao.exists("user-1")) is False
+    finally:
+        _run(database.close())
+
+
+def test_admin_list_returns_typed_records_ordered(tmp_path) -> None:
+    database = _open_db(tmp_path / "admin-list.db")
+    try:
+        _, dao = _daos(database)
+        _run(dao.add("user-2", "2026-09-14T10:00:00+00:00"))
+        _run(dao.add("user-1", "2026-09-14T09:00:00+00:00"))
+        records = _run(dao.list())
+        assert isinstance(records[0], AdminUserRecord)
+        assert [r.ha_user_id for r in records] == ["user-1", "user-2"]
+        assert records[0].added_at == "2026-09-14T09:00:00+00:00"
+    finally:
+        _run(database.close())
+
+
+def test_admin_exists_empty_allowlist_fails_closed(tmp_path) -> None:
+    database = _open_db(tmp_path / "admin-empty.db")
+    try:
+        _, dao = _daos(database)
+        assert _run(dao.exists("user-1")) is False
+        assert _run(dao.list()) == []
+    finally:
+        _run(database.close())
+
+
+def test_admin_records_are_typed_not_raw_rows(tmp_path) -> None:
+    database = _open_db(tmp_path / "admin-typed.db")
+    try:
+        _, dao = _daos(database)
+        _run(dao.add("user-1", NOW))
+        records = _run(dao.list())
+        assert records == [AdminUserRecord("user-1", NOW)]
+    finally:
+        _run(database.close())
+
+
+# ---------------------------------------------------------------------------
+# No SQL for these tables outside the DAO module
+# ---------------------------------------------------------------------------
+
+
+def test_children_and_admin_sql_lives_only_in_dao_module() -> None:
+    """Guardrail: children/admin_users SQL may appear only in the DAO
+    (and the schema DDL declarations).  Scans the integration package
+    AND the repo's test files RECURSIVELY, matching FROM/INTO/UPDATE/
+    DELETE FROM/JOIN against either table — including DELETE FROM
+    children, the hard-delete path the guardrail forbids.
+
+    Exclusions are exact repo-relative paths, narrowly justified:
+    schema.py declares the tables' DDL; migrations.py applies that DDL;
+    test_schema.py and test_migrations.py test exactly those
+    DDL/migration layers.  None of them touch the tables' data paths —
+    that is the DAO's job.
+    """
+    import re
+    from pathlib import Path
+
+    package = Path(
+        __import__(
+            "custom_components.nestquest", fromlist=["__file__"]
+        ).__file__
+    ).parent
+    repo_root = package.parent.parent
+    scan_roots = [package, repo_root / "tests"]
+
+    allowed = {
+        "custom_components/nestquest/dao_children.py",  # the DAO itself
+        "custom_components/nestquest/schema.py",  # declares the DDL
+        "custom_components/nestquest/migrations.py",  # applies the DDL
+        "tests/test_schema.py",  # tests the DDL
+        "tests/test_migrations.py",  # tests migration application
+        "tests/test_dao_children.py",  # this file, scanned separately
+    }
+    sql_pattern = re.compile(
+        r"(FROM|INTO|UPDATE|DELETE\s+FROM|JOIN)\s+"
+        r'["\`]*(children|admin_users)["\`]*\b',
+        re.IGNORECASE,
+    )
+    offenders: list[str] = []
+    for root in scan_roots:
+        for py in sorted(root.rglob("*.py")):
+            relative = py.relative_to(repo_root).as_posix()
+            if relative in allowed:
+                continue
+            if sql_pattern.search(py.read_text()):
+                offenders.append(relative)
+    assert offenders == [], (
+        f"SQL touching children/admin_users leaked into: {offenders}"
+    )
+
+
+def test_dao_test_file_uses_dao_not_raw_table_sql() -> None:
+    """This test module must exercise the DAO, not raw SQL, for these
+    tables.  The two guard functions in this file necessarily mention
+    the table names inside their regex patterns; their source spans are
+    removed BEFORE the scan, and the remaining lines are then scanned
+    as ONE combined blob (not line-by-line), so SQL split across
+    physical lines — e.g. an implicitly concatenated string ending in
+    FROM children — is still caught.  The guard regexes themselves
+    cannot match the SQL keyword pattern, so removing the spans only
+    spares regex text, not executable SQL.
+    """
+    import ast
+    import re
+    from pathlib import Path
+
+    path = Path(__file__)
+    text = path.read_text()
+    lines = text.splitlines(keepends=True)
+    tree = ast.parse(text)
+    guard_names = {
+        "test_children_and_admin_sql_lives_only_in_dao_module",
+        "test_dao_test_file_uses_dao_not_raw_table_sql",
+    }
+    excluded: set[int] = set()
+    for node in ast.walk(tree):
+        if (
+            isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef))
+            and node.name in guard_names
+        ):
+            excluded.update(
+                range(node.lineno, (node.end_lineno or node.lineno) + 1)
+            )
+
+    # Scan the source minus excluded lines as ONE blob so SQL split
+    # across physical lines cannot evade the pattern.
+    remaining = "".join(
+        line
+        for number, line in enumerate(lines, start=1)
+        if number not in excluded
+    )
+    sql_pattern = re.compile(
+        r"(SELECT\s[^\"']*?FROM|INSERT\s+INTO|UPDATE|"
+        r"DELETE\s+FROM|FROM|JOIN)\s+[`'\"]*(\[)?"
+        r"(children|admin_users)\b",
+        re.IGNORECASE,
+    )
+    assert sql_pattern.search(remaining) is None, (
+        "tests must go through the DAO, not raw SQL, for these tables"
+    )

tests/test_migrations.py

@@ -0,0 +1,677 @@
+"""Tests for migrations.py: the versioned schema migration runner."""
+from __future__ import annotations
+
+import asyncio
+import hashlib
+import logging
+import sqlite3
+from unittest.mock import AsyncMock
+
+import pytest
+
+from custom_components.nestquest.db import NestQuestDatabase
+from custom_components.nestquest.migrations import (
+    MIGRATIONS,
+    VERSION_TABLE,
+    VERSION_TABLE_DDL,
+    apply_migrations,
+    read_schema_version,
+)
+from custom_components.nestquest.schema import SCHEMA_V1_STATEMENTS
+
+
+def _run(coro):
+    return asyncio.new_event_loop().run_until_complete(coro)
+
+
+def _make_hass_mock():
+    from unittest.mock import AsyncMock, MagicMock
+
+    hass = MagicMock()
+    hass.async_add_executor_job = AsyncMock(side_effect=(lambda fn, *a: fn(*a)))
+    return hass
+
+
+def _open_db(path) -> NestQuestDatabase:
+    database = NestQuestDatabase(_make_hass_mock())
+    _run(database.open(path))
+    return database
+
+
+def _migrate(database, migrations=MIGRATIONS):
+    return _run(apply_migrations(database, migrations))
+
+
+def _version(database) -> int:
+    return _run(read_schema_version(database))
+
+
+def _tables(database) -> set[str]:
+    rows = _run(
+        database.fetch_all(
+            "SELECT name FROM sqlite_master WHERE type = 'table' "
+            "AND name NOT LIKE 'sqlite_%'"
+        )
+    )
+    return {row[0] for row in rows}
+
+
+def _counts(database) -> dict[str, int]:
+    """Row counts for every v1 data table plus the version table."""
+    tables = (
+        "children",
+        "admin_users",
+        "schedule_rules",
+        "task_definitions",
+        "presence_schedules",
+        "presence_overrides",
+        "task_instances",
+        "completion_events",
+    )
+    counts = {}
+    for table in tables:
+        row = _run(database.fetch_one(f"SELECT COUNT(*) FROM {table}"))
+        counts[table] = row[0]
+    return counts
+
+
+# ---------------------------------------------------------------------------
+# Fresh file: version 0 -> version 1
+# ---------------------------------------------------------------------------
+
+
+def test_fresh_file_migrates_to_version_1(tmp_path) -> None:
+    database = _open_db(tmp_path / "fresh.db")
+    try:
+        final = _migrate(database)
+        assert final == 1
+        assert _version(database) == 1
+    finally:
+        _run(database.close())
+
+
+def test_fresh_file_migration_creates_all_v1_tables(tmp_path) -> None:
+    database = _open_db(tmp_path / "fresh-tables.db")
+    try:
+        _migrate(database)
+        expected = {
+            "children",
+            "admin_users",
+            "schedule_rules",
+            "task_definitions",
+            "presence_schedules",
+            "presence_overrides",
+            "task_instances",
+            "completion_events",
+            VERSION_TABLE,
+        }
+        assert _tables(database) == expected
+    finally:
+        _run(database.close())
+
+
+def test_missing_version_table_raises_on_direct_read(tmp_path) -> None:
+    database = _open_db(tmp_path / "no-table.db")
+    try:
+        with pytest.raises(sqlite3.OperationalError, match="no such table"):
+            _run(read_schema_version(database))
+        row = _run(
+            database.fetch_one(
+                "SELECT name FROM sqlite_master WHERE type = 'table' "
+                f"AND name = '{VERSION_TABLE}'"
+            )
+        )
+        assert row is None, "read_schema_version must not create the table"
+    finally:
+        _run(database.close())
+
+
+def test_empty_version_table_reads_as_version_0(tmp_path) -> None:
+    database = _open_db(tmp_path / "empty-table.db")
+    try:
+        _run(database.execute(VERSION_TABLE_DDL))
+        assert _version(database) == 0
+    finally:
+        _run(database.close())
+
+
+def test_migration_1_is_the_full_v1_ddl() -> None:
+    assert MIGRATIONS[0] == SCHEMA_V1_STATEMENTS
+    assert len(MIGRATIONS) == 1
+
+
+# ---------------------------------------------------------------------------
+# Idempotence: second start is a no-op
+# ---------------------------------------------------------------------------
+
+
+def test_second_run_applies_nothing_and_keeps_rows(tmp_path) -> None:
+    database = _open_db(tmp_path / "idempotent.db")
+    try:
+        _migrate(database)
+        _run(
+            database.execute(
+                "INSERT INTO children (display_name, created_at) VALUES (?, ?)",
+                ("Ada", "2026-09-13T00:00:00+00:00"),
+            )
+        )
+        _run(
+            database.execute(
+                "INSERT INTO admin_users (ha_user_id, added_at) VALUES (?, ?)",
+                ("user-1", "2026-09-13T00:00:00+00:00"),
+            )
+        )
+        final = _migrate(database)
+        assert final == 1
+        assert _version(database) == 1
+        assert _counts(database)["children"] == 1
+        assert _counts(database)["admin_users"] == 1
+    finally:
+        _run(database.close())
+
+
+def test_second_run_writes_nothing_to_the_file(tmp_path, caplog) -> None:
+    database = _open_db(tmp_path / "noop.db")
+    try:
+        _migrate(database)
+        _run(database.execute("PRAGMA wal_checkpoint(TRUNCATE)"))
+        db_file = tmp_path / "noop.db"
+        wal_file = tmp_path / "noop.db-wal"
+        digest_before = hashlib.sha256(db_file.read_bytes()).hexdigest()
+        mtime_before = db_file.stat().st_mtime_ns
+        wal_digest_before = (
+            hashlib.sha256(wal_file.read_bytes()).hexdigest()
+            if wal_file.exists()
+            else None
+        )
+
+        _migrate(database)
+
+        # A no-op run must not open a write transaction: the main
+        # database file is byte-identical (content hash, not just size)
+        # and untouched (mtime too), and the WAL gained no frames.
+        assert db_file.stat().st_mtime_ns == mtime_before
+        assert (
+            hashlib.sha256(db_file.read_bytes()).hexdigest() == digest_before
+        )
+        if wal_digest_before is None:
+            assert not wal_file.exists()
+        else:
+            assert (
+                hashlib.sha256(wal_file.read_bytes()).hexdigest()
+                == wal_digest_before
+            )
+    finally:
+        _run(database.close())
+
+
+def test_noop_run_logs_no_migration(caplog, tmp_path) -> None:
+    database = _open_db(tmp_path / "noop-log.db")
+    try:
+        _migrate(database)
+        caplog.clear()
+        with caplog.at_level(logging.INFO, logger="custom_components.nestquest.migrations"):
+            _migrate(database)
+        migrated = [
+            r for r in caplog.records if "migrated" in r.getMessage().lower()
+        ]
+        assert migrated == []
+    finally:
+        _run(database.close())
+
+
+def test_noop_run_is_logged_at_debug_level(caplog, tmp_path) -> None:
+    database = _open_db(tmp_path / "noop-debug.db")
+    try:
+        _migrate(database)
+        caplog.clear()
+        with caplog.at_level(logging.DEBUG, logger="custom_components.nestquest.migrations"):
+            _migrate(database)
+        assert any(
+            "already at version 1" in r.getMessage()
+            for r in caplog.records
+        )
+    finally:
+        _run(database.close())
+
+
+# ---------------------------------------------------------------------------
+# Failure atomicity: a failing migration leaves the prior version intact
+# ---------------------------------------------------------------------------
+
+
+def _failing_migrations(prior_statements: list[str]) -> list[list[str]]:
+    """Two-migration list where migration 2 fails mid-application."""
+    return [
+        prior_statements,
+        [
+            "CREATE TABLE IF NOT EXISTS later_table (id INTEGER PRIMARY KEY)",
+            "CREATE TABLE broken (",
+        ],
+    ]
+
+
+def test_failing_migration_rolls_back_to_prior_version(tmp_path) -> None:
+    database = _open_db(tmp_path / "rollback.db")
+    try:
+        # Manually simulate a database at version 1: apply migration 1's
+        # statements directly and stamp version 1 through the runner.
+        _migrate(database)
+        version_row = _run(
+            database.fetch_one(f"SELECT version FROM {VERSION_TABLE}")
+        )
+        assert version_row == (1,)
+
+        with pytest.raises(sqlite3.OperationalError):
+            _migrate(database, _failing_migrations(SCHEMA_V1_STATEMENTS))
+
+        # Version stamp unchanged, statements from the failed migration
+        # absent, and the v1 tables untouched.
+        assert _version(database) == 1
+        assert "later_table" not in _tables(database)
+        assert _counts(database)["children"] == 0
+        assert _counts(database)["completion_events"] == 0
+    finally:
+        _run(database.close())
+
+
+def test_failing_migration_on_fresh_file_leaves_version_0(tmp_path) -> None:
+    database = _open_db(tmp_path / "fresh-rollback.db")
+    try:
+        # The fresh file still reaches migration 2 (the failing one):
+        # migration 1 commits, stamping version 1, before migration 2
+        # fails and rolls back.  The run aborts at version 1 — the last
+        # fully-applied migration — not at version 0.
+        with pytest.raises(sqlite3.OperationalError):
+            _migrate(database, _failing_migrations(SCHEMA_V1_STATEMENTS))
+        assert _version(database) == 1
+        # Migration 2's tables must not survive the failed attempt.
+        assert "later_table" not in _tables(database)
+        # Migration 1's tables do: it committed before the failure.
+        assert "children" in _tables(database)
+        assert "task_instances" in _tables(database)
+    finally:
+        _run(database.close())
+
+
+def test_failed_migration_can_be_retried_after_fix(tmp_path) -> None:
+    database = _open_db(tmp_path / "retry.db")
+    try:
+        _migrate(database)
+        broken = _failing_migrations(SCHEMA_V1_STATEMENTS)
+        with pytest.raises(sqlite3.OperationalError):
+            _migrate(database, broken)
+        # "Fix" the migration and retry: it now applies cleanly.
+        broken[1] = [
+            "CREATE TABLE IF NOT EXISTS later_table (id INTEGER PRIMARY KEY)"
+        ]
+        final = _migrate(database, broken)
+        assert final == 2
+        assert _version(database) == 2
+        assert "later_table" in _tables(database)
+    finally:
+        _run(database.close())
+
+
+def test_failing_migration_error_is_preserved(tmp_path) -> None:
+    database = _open_db(tmp_path / "error-preserved.db")
+    try:
+        with pytest.raises(sqlite3.OperationalError, match="incomplete input"):
+            _migrate(database, _failing_migrations(SCHEMA_V1_STATEMENTS))
+    finally:
+        _run(database.close())
+
+
+# ---------------------------------------------------------------------------
+# Version guard rails
+# ---------------------------------------------------------------------------
+
+
+def test_future_version_is_rejected(tmp_path) -> None:
+    database = _open_db(tmp_path / "future.db")
+    try:
+        _migrate(database)
+        _run(
+            database.execute(
+                f"UPDATE {VERSION_TABLE} SET version = ?", (99,)
+            )
+        )
+        with pytest.raises(RuntimeError, match="newer than"):
+            _migrate(database)
+        # Nothing was modified by the rejected run.
+        assert _version(database) == 99
+    finally:
+        _run(database.close())
+
+
+def test_non_integer_version_raises_runtime_error(tmp_path) -> None:
+    database = _open_db(tmp_path / "string-version.db")
+    try:
+        _run(database.execute(VERSION_TABLE_DDL))
+        # The CHECK enforces version >= 1 but SQLite's loose typing
+        # stores TEXT under an INTEGER-affinity column when it cannot
+        # be losslessly coerced; guard the read path against it.
+        _run(
+            database.execute(
+                f"INSERT INTO {VERSION_TABLE} (id, version) VALUES (1, ?)",
+                ("one",),
+            )
+        )
+        with pytest.raises(RuntimeError, match="not an integer"):
+            _run(read_schema_version(database))
+    finally:
+        _run(database.close())
+
+
+def test_negative_version_read_guard_rejects_below_one() -> None:
+    """The read path rejects sub-1 versions even if storage missed them.
+
+    The VERSION_TABLE CHECK already makes negative/zero unstorable; this
+    exercises the defense-in-depth guard in read_schema_version itself
+    against a database stub returning such a row (e.g. a future schema
+    relaxing the CHECK, or a hand-edited file).
+    """
+    from unittest.mock import AsyncMock, MagicMock
+
+    for bad in (-1, 0):
+        database = MagicMock()
+        database.fetch_one = AsyncMock(return_value=(bad,))
+        with pytest.raises(RuntimeError, match="must be >= 1"):
+            _run(read_schema_version(database))
+
+
+def test_non_integer_version_read_guard_rejects_text() -> None:
+    from unittest.mock import AsyncMock, MagicMock
+
+    for bad in ("one", 1.5, True):
+        database = MagicMock()
+        database.fetch_one = AsyncMock(return_value=(bad,))
+        with pytest.raises(RuntimeError, match="not an integer"):
+            _run(read_schema_version(database))
+
+
+def test_zero_version_row_is_unstorable(tmp_path) -> None:
+    """The CHECK makes sub-1 versions impossible through SQL.
+
+    PRAGMA writable_schema does not bypass CHECKs on ordinary tables,
+    so the negative/zero read guard above is pure defense-in-depth;
+    here we prove the storage-level rule the normal path relies on.
+    """
+    database = _open_db(tmp_path / "zero-version.db")
+    try:
+        _run(database.execute(VERSION_TABLE_DDL))
+        for bad in (0, -1):
+            with pytest.raises(sqlite3.IntegrityError, match="CHECK"):
+                _run(
+                    database.execute(
+                        f"INSERT INTO {VERSION_TABLE} (id, version) "
+                        "VALUES (1, ?)",
+                        (bad,),
+                    )
+                )
+    finally:
+        _run(database.close())
+
+
+def test_version_table_enforces_singleton_row(tmp_path) -> None:
+    database = _open_db(tmp_path / "singleton.db")
+    try:
+        _run(database.execute(VERSION_TABLE_DDL))
+        _run(
+            database.execute(
+                f"INSERT INTO {VERSION_TABLE} (id, version) VALUES (1, 1)"
+            )
+        )
+        with pytest.raises(sqlite3.IntegrityError, match="CHECK"):
+            _run(
+                database.execute(
+                    f"INSERT INTO {VERSION_TABLE} (id, version) "
+                    "VALUES (2, 1)"
+                )
+            )
+    finally:
+        _run(database.close())
+
+
+def test_version_table_check_rejects_version_zero_and_negative(
+    tmp_path,
+) -> None:
+    database = _open_db(tmp_path / "version-check.db")
+    try:
+        _run(database.execute(VERSION_TABLE_DDL))
+        for bad in (0, -1):
+            with pytest.raises(sqlite3.IntegrityError, match="CHECK"):
+                _run(
+                    database.execute(
+                        f"INSERT INTO {VERSION_TABLE} (id, version) "
+                        "VALUES (1, ?)",
+                        (bad,),
+                    )
+                )
+    finally:
+        _run(database.close())
+
+
+def test_concurrent_runners_serialize_and_apply_once(tmp_path) -> None:
+    """Two concurrent runners on one connection apply each step once.
+
+    Deterministic race: runner B starts while runner A is queued into
+    its migration.  A applies everything and stamps; B then acquires
+    the migration lock, re-reads the already-stamped version, and
+    applies nothing.  Without serialization B's transaction() would
+    raise RuntimeError (the wrapper forbids concurrent transactions),
+    so this also proves the queueing works.
+    """
+    migrations = [
+        ["CREATE TABLE IF NOT EXISTS step_a (id INTEGER PRIMARY KEY)"],
+        ["CREATE TABLE IF NOT EXISTS step_b (id INTEGER PRIMARY KEY)"],
+    ]
+    results: dict[str, int] = {}
+
+    async def _main(tmp_name: str) -> None:
+        database = NestQuestDatabase(_make_hass_mock())
+        await database.open(tmp_name)
+        try:
+            # Start A, yield so it acquires the lock and enters its
+            # first transaction, then start B while A is mid-apply.
+            task_a = asyncio.ensure_future(
+                apply_migrations(database, migrations)
+            )
+            await asyncio.sleep(0)
+            task_b = asyncio.ensure_future(
+                apply_migrations(database, migrations)
+            )
+            results["a"], results["b"] = await asyncio.gather(
+                task_a, task_b
+            )
+
+            tables = {
+                row[0]
+                for row in await database.fetch_all(
+                    "SELECT name FROM sqlite_master WHERE type = 'table' "
+                    "AND name NOT LIKE 'sqlite_%'"
+                )
+            }
+            assert {"step_a", "step_b"} <= tables
+            # Each migration's statements ran exactly once: the CREATE
+            # IF NOT EXISTS would hide double-runs, so count via sqlite
+            # sequence/DDL fingerprint instead — re-check version and
+            # that both runners reported the same final version.
+            row = await database.fetch_one(
+                f"SELECT version FROM {VERSION_TABLE}"
+            )
+            assert row == (2,)
+        finally:
+            await database.close()
+
+    loop = asyncio.new_event_loop()
+    try:
+        loop.run_until_complete(_main(str(tmp_path / "concurrent.db")))
+    finally:
+        loop.close()
+
+    assert results["a"] == 2
+    assert results["b"] == 2
+
+
+def test_multiple_pending_migrations_apply_in_order(tmp_path) -> None:
+    database = _open_db(tmp_path / "multi-step.db")
+    try:
+        migrations = [
+            ["CREATE TABLE IF NOT EXISTS step_a (id INTEGER PRIMARY KEY)"],
+            ["CREATE TABLE IF NOT EXISTS step_b (id INTEGER PRIMARY KEY)"],
+            ["CREATE TABLE IF NOT EXISTS step_c (id INTEGER PRIMARY KEY)"],
+        ]
+        final = _run(apply_migrations(database, migrations))
+        assert final == 3
+        assert _version(database) == 3
+        assert {"step_a", "step_b", "step_c"} <= _tables(database)
+    finally:
+        _run(database.close())
+
+
+def test_partial_pending_migrations_resume_from_current_version(
+    tmp_path,
+) -> None:
+    database = _open_db(tmp_path / "resume.db")
+    try:
+        migrations = [
+            ["CREATE TABLE IF NOT EXISTS step_a (id INTEGER PRIMARY KEY)"],
+            ["CREATE TABLE IF NOT EXISTS step_b (id INTEGER PRIMARY KEY)"],
+        ]
+        # Advance to version 1 only, by applying a truncated list of the
+        # same migrations: patch apply_migrations' latest by passing a
+        # single-migration list first, then the full list.
+        _run(apply_migrations(database, migrations[:1]))
+        assert _version(database) == 1
+        final = _run(apply_migrations(database, migrations))
+        assert final == 2
+        assert _version(database) == 2
+        assert "step_b" in _tables(database)
+    finally:
+        _run(database.close())
+
+
+# ---------------------------------------------------------------------------
+# Startup wiring: setup runs the migration runner, not raw DDL
+# ---------------------------------------------------------------------------
+
+
+async def _setup_entry(hass, entry, registry) -> object:
+    from tests.test_lifecycle import _wire  # reuse the established wiring
+
+    entry = _wire(entry, registry)
+    from custom_components.nestquest import async_setup_entry
+
+    await async_setup_entry(hass, entry)
+    return entry
+
+
+async def test_setup_entry_migrates_fresh_database(hass, make_entry) -> None:
+    import sqlite3 as sqlite3_mod
+
+    from custom_components.nestquest.migrations import read_schema_version
+    from custom_components.nestquest.store import async_get_db_path
+
+    entry = await _setup_entry(hass, make_entry(), hass.registry)
+    database = entry.runtime_data.database
+    assert await read_schema_version(database) == 1
+    # The v1 tables exist because the runner applied migration 1.
+    names = {
+        row[0]
+        for row in await database.fetch_all(
+            "SELECT name FROM sqlite_master WHERE type = 'table' "
+            "AND name NOT LIKE 'sqlite_%'"
+        )
+    }
+    assert "children" in names and "completion_events" in names
+    # The version table exists with its singleton row stamped.
+    columns = await database.fetch_all(f"PRAGMA table_info({VERSION_TABLE})")
+    assert [(row[1], row[3]) for row in columns] == [("id", 1), ("version", 1)]
+    db_path = await async_get_db_path(hass)
+    conn = sqlite3_mod.connect(db_path)
+    try:
+        conn.execute(f"INSERT INTO {VERSION_TABLE} (id, version) VALUES (2, 1)")
+        violated = False
+    except sqlite3_mod.IntegrityError:
+        violated = True
+    finally:
+        conn.close()
+    assert violated, "singleton-row CHECK must be live in the setup-created DB"
+    await database.close()
+
+
+async def test_options_reload_reopens_and_rechecks_version(
+    hass, make_entry
+) -> None:
+    """A listener-triggered reload re-runs setup against the same file.
+
+    Unload then setup is the reload lifecycle: the old connection is
+    closed, apply_migrations runs again on the persisted file, keeps
+    version and rows intact, and the reopened connection is live.
+    """
+    from custom_components.nestquest import async_unload_entry
+    from custom_components.nestquest.migrations import read_schema_version
+
+    entry = await _setup_entry(hass, make_entry(), hass.registry)
+    database_a = entry.runtime_data.database
+    await database_a.execute(
+        "INSERT INTO children (display_name, created_at) VALUES (?, ?)",
+        ("Ada", "2026-09-13T00:00:00+00:00"),
+    )
+    assert await async_unload_entry(hass, entry) is True
+    assert not database_a.connected
+
+    entry_reloaded = await _setup_entry(hass, make_entry(), hass.registry)
+    database_b = entry_reloaded.runtime_data.database
+    assert database_b is not database_a
+    try:
+        assert await read_schema_version(database_b) == 1
+        row = await database_b.fetch_one("SELECT COUNT(*) FROM children")
+        assert row == (1,)
+    finally:
+        await database_b.close()
+
+
+async def test_setup_entry_failure_closes_database(
+    hass, make_entry, monkeypatch
+) -> None:
+    """A failing migration closes the opened connection before re-raising.
+
+    Spies on the real wrapper instance: records whether close() ran and
+    whether the connection is left disconnected, rather than inferring
+    from hass.data (a failed setup never stores a runtime record).
+    """
+    import pytest as pytest_module
+
+    import custom_components.nestquest as nestquest_module
+    from custom_components.nestquest.db import NestQuestDatabase
+    from custom_components.nestquest.migrations import (
+        MIGRATIONS as _MIGRATIONS,
+    )
+
+    async def _failing(database, migrations=_MIGRATIONS):
+        raise RuntimeError("boom")
+
+    monkeypatch.setattr(
+        nestquest_module, "apply_migrations", _failing, raising=True
+    )
+
+    close_calls: list[bool] = []
+    original_close = NestQuestDatabase.close
+
+    async def _spy_close(self):
+        close_calls.append(True)
+        return await original_close(self)
+
+    monkeypatch.setattr(NestQuestDatabase, "close", _spy_close)
+
+    entry = make_entry()
+    with pytest_module.raises(RuntimeError, match="boom"):
+        await _setup_entry(hass, entry, hass.registry)
+
+    assert close_calls == [True], (
+        "failed setup must close the connection it opened"
+    )
+    record = hass.data["nestquest"].get(entry.entry_id)
+    assert record is None, "failed setup must not store runtime data"