Generate the week's Supply run from its plan

Add internal/shopping with Generate(weekStart), one entry point for the
first generation and every regeneration. It builds one group per plan
day (dinner_id, date, position by date) and one item per ingredient of
the dinner's recipe, in ingredient order, reusing the values recipe
grounding stored: a fetched recipe's normalized name with qty and unit
joined for display, or a manual recipe's line as typed with no qty. A
day whose dinner has no recipe or no ingredients gets no group and is
reported in Skipped. Regenerating keeps the id and needed flag of each
item whose (dinner_id, name) is unchanged, matching repeated names in
order; new items are needed and items no longer planned are removed. It
is deterministic and makes no model call. A frozen list is refused.

Migration 0016 makes shopping_lists.title nullable (never empty) so a
list exists untitled until the AI titles it, and adds shopping_groups.date.

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

migrations/0016_shopping_list_untitled.sql

@@ -0,0 +1,81 @@
+-- 0016_shopping_list_untitled: a Supply run is generated from the plan
+-- before it has a title, and stays untitled when the AI cannot write one,
+-- so shopping_lists.title becomes nullable; an untitled list shows its
+-- week label instead. A title is never empty. Each group also keeps the
+-- plan day it shops for, so a list read back, or frozen into the Supply
+-- archive, says which day each dinner was planned on.
+-- SQLite cannot drop a NOT NULL constraint or add a NOT NULL column
+-- without a default, so the three shopping tables are rebuilt as 0012
+-- does: copy the rows aside, drop the tables children first, create them
+-- again, copy the rows back parents first and drop the copies. A group
+-- takes the date its dinner has on its list's plan; a group whose dinner
+-- is not on that plan has no date and fails the migration. Nothing else
+-- references the shopping tables.
+
+CREATE TABLE shopping_items_copy AS SELECT * FROM shopping_items;
+CREATE TABLE shopping_groups_copy AS SELECT * FROM shopping_groups;
+CREATE TABLE shopping_lists_copy AS SELECT * FROM shopping_lists;
+
+DROP TABLE shopping_items;
+DROP TABLE shopping_groups;
+DROP TABLE shopping_lists;
+
+CREATE TABLE shopping_lists (
+	id              TEXT NOT NULL PRIMARY KEY,
+	week_start      TEXT NOT NULL UNIQUE,
+	plan_id         TEXT NOT NULL REFERENCES week_plans (id),
+	title           TEXT CHECK (title <> ''), -- NULL until the AI titles it
+	status          TEXT NOT NULL CHECK (status IN ('current', 'archived')),
+	sent_to_chat_at TEXT,
+	frozen_at       TEXT,
+	created_at      TEXT NOT NULL,
+	updated_at      TEXT NOT NULL
+);
+
+CREATE TABLE shopping_groups (
+	id         TEXT    NOT NULL PRIMARY KEY,
+	list_id    TEXT    NOT NULL REFERENCES shopping_lists (id),
+	dinner_id  TEXT    NOT NULL REFERENCES dinners (id),
+	date       TEXT    NOT NULL, -- the plan day, household-local YYYY-MM-DD
+	position   INTEGER NOT NULL,
+	created_at TEXT    NOT NULL,
+	updated_at TEXT    NOT NULL
+);
+
+CREATE TABLE shopping_items (
+	id         TEXT    NOT NULL PRIMARY KEY,
+	group_id   TEXT    NOT NULL REFERENCES shopping_groups (id),
+	name       TEXT    NOT NULL,
+	qty        TEXT,
+	needed     INTEGER NOT NULL DEFAULT 1 CHECK (needed IN (0, 1)),
+	position   INTEGER NOT NULL,
+	created_at TEXT    NOT NULL,
+	updated_at TEXT    NOT NULL
+);
+
+INSERT INTO shopping_lists (
+	id, week_start, plan_id, title, status, sent_to_chat_at, frozen_at, created_at, updated_at
+)
+SELECT id, week_start, plan_id, title, status, sent_to_chat_at, frozen_at, created_at, updated_at
+FROM shopping_lists_copy;
+
+INSERT INTO shopping_groups (id, list_id, dinner_id, date, position, created_at, updated_at)
+SELECT
+	shopping_groups_copy.id, shopping_groups_copy.list_id, shopping_groups_copy.dinner_id,
+	(
+		SELECT MIN(plan_days.date)
+		FROM plan_days
+		JOIN shopping_lists_copy ON shopping_lists_copy.plan_id = plan_days.plan_id
+		WHERE shopping_lists_copy.id = shopping_groups_copy.list_id
+			AND plan_days.dinner_id = shopping_groups_copy.dinner_id
+	),
+	shopping_groups_copy.position, shopping_groups_copy.created_at, shopping_groups_copy.updated_at
+FROM shopping_groups_copy;
+
+INSERT INTO shopping_items (id, group_id, name, qty, needed, position, created_at, updated_at)
+SELECT id, group_id, name, qty, needed, position, created_at, updated_at
+FROM shopping_items_copy;
+
+DROP TABLE shopping_items_copy;
+DROP TABLE shopping_groups_copy;
+DROP TABLE shopping_lists_copy;

migrations/queries/shopping.sql

@@ -0,0 +1,60 @@
+-- name: GetShoppingList :one
+-- The Supply run of the week starting week_start. Returns sql.ErrNoRows
+-- when there is none.
+SELECT * FROM shopping_lists
+WHERE week_start = ?;
+
+-- name: CreateShoppingList :exec
+-- A new, untitled Supply run: the title is written later, by the AI.
+INSERT INTO shopping_lists (id, week_start, plan_id, status, created_at, updated_at)
+VALUES (?, ?, ?, 'current', ?, ?);
+
+-- name: RegenerateShoppingList :exec
+-- Records a generation of list id from plan plan_id.
+UPDATE shopping_lists
+SET plan_id = ?, updated_at = ?
+WHERE id = ?;
+
+-- name: ListShoppingGroups :many
+-- The groups of list list_id, in list order.
+SELECT * FROM shopping_groups
+WHERE list_id = ?
+ORDER BY position, id;
+
+-- name: ListShoppingItems :many
+-- The items of list list_id with their group's dinner, in list order: by
+-- group, then by item.
+SELECT sqlc.embed(shopping_items), shopping_groups.dinner_id
+FROM shopping_items
+JOIN shopping_groups ON shopping_groups.id = shopping_items.group_id
+WHERE shopping_groups.list_id = ?
+ORDER BY shopping_groups.position, shopping_items.position, shopping_items.id;
+
+-- name: CreateShoppingGroup :exec
+INSERT INTO shopping_groups (id, list_id, dinner_id, date, position, created_at, updated_at)
+VALUES (?, ?, ?, ?, ?, ?, ?);
+
+-- name: MoveShoppingGroup :exec
+UPDATE shopping_groups
+SET position = ?, updated_at = ?
+WHERE id = ?;
+
+-- name: DeleteShoppingGroup :exec
+DELETE FROM shopping_groups
+WHERE id = ?;
+
+-- name: CreateShoppingItem :exec
+-- A new item is needed until the household marks it "have it".
+INSERT INTO shopping_items (id, group_id, name, qty, needed, position, created_at, updated_at)
+VALUES (?, ?, ?, ?, 1, ?, ?, ?);
+
+-- name: MoveShoppingItem :exec
+-- Places item id in group group_id at position with quantity qty; its
+-- name and needed flag are kept.
+UPDATE shopping_items
+SET group_id = ?, qty = ?, position = ?, updated_at = ?
+WHERE id = ?;
+
+-- name: DeleteShoppingItem :exec
+DELETE FROM shopping_items
+WHERE id = ?;