Add debug Remove entry, Show more auto-picker, and update docs.

DELETE /api/paintings/:id removes works and image files with gallery refresh and catalog navigation; Show more opens the search modal on load; documentation updated for migrate schema and debug workflow.

Co-authored-by: Cursor <cursoragent@cursor.com>

Documentation/DB_structure.md

@@ -1,6 +1,6 @@
 # Art Gallery — database structure
 
-PostgreSQL schema for the virtual gallery. Canonical DDL is intended to live in `db/schema.sql` when checked in; this document describes the logical model either way.
+PostgreSQL schema for the virtual gallery. Canonical DDL lives in **`db/schema.sql`**; **`server/migrate.js`** (`npm run migrate`) applies that file plus idempotent incremental scripts in `db/migrate-*.sql`. This document describes the logical model.
 
 Connection settings come from `.env` (see [setup.md](setup.md)).
 
@@ -189,7 +189,7 @@ Unique index on `(painting_id, source_type, source_painting_id, source_artist_id
 
 ## First-time setup
 
-The `gallery` database user needs `CREATE` on schema `public` for migrations. If tables cannot be created, run admin grants as PostgreSQL superuser before `npm run migrate`:
+The `gallery` database user needs `CREATE` on schema `public` for migrations. If tables cannot be created, run **`db/setup-admin.sql`** as PostgreSQL superuser (or the grants below) before `npm run migrate`:
 
 ```sql
 GRANT CREATE ON SCHEMA public TO gallery;