Add sqlc configuration and core queries

sqlc.yaml (sqlite, schema migrations/, queries migrations/queries/)
generates internal/db with emit_interface. Queries cover dinners (create,
get, list by status, update, archive, set favorite), recipes with
ingredients and steps (upsert by source_url, get, replace children),
photos (insert, get by sha256) and get/upsert for the five settings
singletons. Repository tests run every query against a migrated temp
database.

make sqlc regenerates with the pinned sqlc v1.31.1 (dev tool only, not in
go.mod); make sqlc-check regenerates and fails on any drift in
internal/db, and CI runs it after make test.

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

migrations/queries/recipes.sql

@@ -0,0 +1,65 @@
+-- name: UpsertRecipe :one
+-- A recipe is keyed by source_url: re-fetching the same URL updates the
+-- existing row and keeps its id and created_at, which the returned row
+-- carries. Replace its ingredients and steps in the same transaction with
+-- DeleteRecipeIngredients/DeleteRecipeSteps then the Create queries.
+INSERT INTO recipes (
+	id, source_url, site_name, title, total_minutes, prep_minutes,
+	cook_minutes, yield, raw_jsonld, fetched_at, created_at, updated_at
+) VALUES (
+	?, ?, ?, ?, ?, ?,
+	?, ?, ?, ?, ?, ?
+)
+ON CONFLICT (source_url) DO UPDATE SET
+	site_name = excluded.site_name,
+	title = excluded.title,
+	total_minutes = excluded.total_minutes,
+	prep_minutes = excluded.prep_minutes,
+	cook_minutes = excluded.cook_minutes,
+	yield = excluded.yield,
+	raw_jsonld = excluded.raw_jsonld,
+	fetched_at = excluded.fetched_at,
+	updated_at = excluded.updated_at
+RETURNING *;
+
+-- name: GetRecipe :one
+SELECT * FROM recipes
+WHERE id = ?;
+
+-- name: GetRecipeBySourceURL :one
+SELECT * FROM recipes
+WHERE source_url = ?;
+
+-- name: CreateRecipeIngredient :exec
+INSERT INTO recipe_ingredients (
+	id, recipe_id, position, raw_text, name, qty, unit, note,
+	created_at, updated_at
+) VALUES (
+	?, ?, ?, ?, ?, ?, ?, ?,
+	?, ?
+);
+
+-- name: ListRecipeIngredients :many
+SELECT * FROM recipe_ingredients
+WHERE recipe_id = ?
+ORDER BY position, id;
+
+-- name: DeleteRecipeIngredients :exec
+DELETE FROM recipe_ingredients
+WHERE recipe_id = ?;
+
+-- name: CreateRecipeStep :exec
+INSERT INTO recipe_steps (
+	id, recipe_id, position, text, created_at, updated_at
+) VALUES (
+	?, ?, ?, ?, ?, ?
+);
+
+-- name: ListRecipeSteps :many
+SELECT * FROM recipe_steps
+WHERE recipe_id = ?
+ORDER BY position, id;
+
+-- name: DeleteRecipeSteps :exec
+DELETE FROM recipe_steps
+WHERE recipe_id = ?;