Reject coerced and out-of-range skip_on_away values

Review remediation for PR #194:
- Admin create/edit request models use StrictBool so JSON 0/1 and
  "true"/"false" are 422 instead of being coerced to a bool.
- Fresh-schema quest_definitions gains CHECK (skip_on_away IN (0, 1));
  migrated databases (column added without the CHECK) are guarded by a
  DAO validator applied at every write path that takes the flag.
- QuestDefinitionsDao.update() accepts skip_on_away (None leaves it
  unchanged), validated like the other write paths.

Task: ded75ab8-0219-4d52-aefa-82c09e0b5e6b

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_schema.py

@@ -634,6 +634,30 @@ def test_schedule_rules_rule_type_check_enforced(tmp_path) -> None:
         _run(database.close())
 
 
+@pytest.mark.parametrize("bad_flag", [2, -1])
+def test_quest_definitions_skip_on_away_check_enforced(
+    tmp_path, bad_flag
+) -> None:
+    database = _open_db(tmp_path / f"skip-on-away-{bad_flag}.db")
+    try:
+        _apply(database)
+        _child(database)
+        _insert_rule(database)
+        with pytest.raises(sqlite3.IntegrityError, match="CHECK"):
+            _insert_definition(database, skip_on_away=bad_flag)
+        definition_id = _insert_definition(database, skip_on_away=0)
+        with pytest.raises(sqlite3.IntegrityError, match="CHECK"):
+            _run(
+                database.execute(
+                    "UPDATE quest_definitions SET skip_on_away = ? "
+                    "WHERE id = ?",
+                    (bad_flag, definition_id),
+                )
+            )
+    finally:
+        _run(database.close())
+
+
 def test_schedule_rules_interval_zero_fails(tmp_path) -> None:
     database = _open_db(tmp_path / "interval-zero.db")
     try: