feat(review): #90 photo strip — keep/remove, drag-reorder, leftmost=primary, persist

REVIEW-5 / PUBLISH-45: owner edits the stored photo lineup in Review — tap a
card to keep/remove, drag to reorder, leftmost kept photo = primary (Woo
cover). The kept set must contain a clean calibration + its dimension-overlay
copy; publish is blocked until it does.

- backend: role column on slab_photos (schema + idempotent _migrate ALTER),
  role in photo CRUD + new DELETE endpoint, Woo image order by role-rank
  (clean→overlay→batch) per PUBLISH-45
- frontend: Review photo strip (render from listPhotos, keep/remove,
  HTML5 drag-reorder, dynamic PRIMARY badge from .primary class),
  persistLineup() re-seq kept + drop removed before entering Publish
- tests: lineup.ts unit, e2e review-photo-strip.spec, backend role + order

Refs: #90, REVIEW-5, PUBLISH-45

backend/db/__init__.py

@@ -80,6 +80,21 @@ _M3_TABLES = [
 ]
 
 
+def _migrate(conn: sqlite3.Connection) -> None:
+    """Idempotent column additions for volumes created before a column existed.
+
+    `CREATE TABLE IF NOT EXISTS` in schema.sql is a no-op on an existing table,
+    so new columns must be added here. Each guard is a no-op once the column is
+    present. #90 adds slab_photos.role (lineup kind) for the Review photo strip.
+    """
+    photo_cols = {r[1] for r in conn.execute("PRAGMA table_info(slab_photos)").fetchall()}
+    if photo_cols and "role" not in photo_cols:
+        conn.execute(
+            "ALTER TABLE slab_photos ADD COLUMN role TEXT NOT NULL DEFAULT 'batch' "
+            "CHECK(role IN ('calibration','overlay','batch'))"
+        )
+
+
 def init_db(db_path: str | None = None) -> sqlite3.Connection:
     conn = get_connection(db_path)
     schema_path = _get_schema_path()
@@ -99,6 +114,10 @@ def init_db(db_path: str | None = None) -> sqlite3.Connection:
             conn.executescript(schema)
         conn.execute("INSERT OR REPLACE INTO schema_version (version) VALUES (1)")
         conn.commit()
+    # Safe to run every boot: no-op once the columns exist.
+    with _lock:
+        _migrate(conn)
+        conn.commit()
 
     return conn