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>

internal/db/photos.sql.go

@@ -0,0 +1,86 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+// source: photos.sql
+
+package db
+
+import (
+	"context"
+)
+
+const createPhoto = `-- name: CreatePhoto :one
+INSERT INTO photos (
+	id, source_url, local_path, width, height, sha256, fetched_at,
+	created_at, updated_at
+) VALUES (
+	?, ?, ?, ?, ?, ?, ?,
+	?, ?
+)
+RETURNING id, source_url, local_path, width, height, sha256, fetched_at, created_at, updated_at
+`
+
+type CreatePhotoParams struct {
+	ID        string
+	SourceUrl string
+	LocalPath string
+	Width     int64
+	Height    int64
+	Sha256    string
+	FetchedAt string
+	CreatedAt string
+	UpdatedAt string
+}
+
+func (q *Queries) CreatePhoto(ctx context.Context, arg CreatePhotoParams) (Photo, error) {
+	row := q.db.QueryRowContext(ctx, createPhoto,
+		arg.ID,
+		arg.SourceUrl,
+		arg.LocalPath,
+		arg.Width,
+		arg.Height,
+		arg.Sha256,
+		arg.FetchedAt,
+		arg.CreatedAt,
+		arg.UpdatedAt,
+	)
+	var i Photo
+	err := row.Scan(
+		&i.ID,
+		&i.SourceUrl,
+		&i.LocalPath,
+		&i.Width,
+		&i.Height,
+		&i.Sha256,
+		&i.FetchedAt,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const getPhotoBySHA256 = `-- name: GetPhotoBySHA256 :one
+SELECT id, source_url, local_path, width, height, sha256, fetched_at, created_at, updated_at FROM photos
+WHERE sha256 = ?
+ORDER BY id
+LIMIT 1
+`
+
+// Finds stored image bytes by content hash. The schema does not make sha256
+// unique, so the earliest-created (lowest id) match is returned.
+func (q *Queries) GetPhotoBySHA256(ctx context.Context, sha256 string) (Photo, error) {
+	row := q.db.QueryRowContext(ctx, getPhotoBySHA256, sha256)
+	var i Photo
+	err := row.Scan(
+		&i.ID,
+		&i.SourceUrl,
+		&i.LocalPath,
+		&i.Width,
+		&i.Height,
+		&i.Sha256,
+		&i.FetchedAt,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}