Add proper .gitignore to exclude temporary files

- Exclude tmpclaude-* temporary directories
- Exclude database backup directories and exports
- Clean up temporary files from disk

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

.gitignore

@@ -13,6 +13,9 @@ Desktop.ini
 # Temp files
 *.tmp
 ~$*
+tmpclaude-*/
+db/.form_backups/
+db/frm_*.txt
 
 # Scripts temporaires
 scripts/create_db.ps1