Discover NocoDB table IDs dynamically instead of hardcoding them

Table IDs are now fetched at runtime via the NocoDB meta API using
VITE_NOCODB_BASE_ID, so the same code works against any NocoDB instance
(local or Cloudron). Also adds a migration script for moving data between
instances with correct FK remapping.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.env.example

@@ -1,6 +1,7 @@
 # NocoDB (primary data source)
 VITE_NOCODB_URL=http://localhost:8090
 VITE_NOCODB_TOKEN=your_token_here
+VITE_NOCODB_BASE_ID=your_base_id_here
 
 # Google Sheets (fallback if NocoDB fails)
 VITE_SHEETS_ID=your_spreadsheet_id_here