fix: phased restore for BLOB databases to prevent lock exhaustion OOM

- Auto-detect large objects in pg_restore dumps
- Split restore into pre-data, data, post-data phases
- Each phase commits and releases locks before next
- Prevents 'out of shared memory' / max_locks_per_transaction errors
- Updated error hints with better guidance for lock exhaustion

internal/checks/error_hints.go

@@ -68,8 +68,8 @@ func ClassifyError(errorMsg string) *ErrorClassification {
 			Type:     "critical",
 			Category: "locks",
 			Message:  errorMsg,
-			Hint:     "Lock table exhausted - typically caused by large objects in parallel restore",
-			Action:   "Increase max_locks_per_transaction in postgresql.conf to 512 or higher",
+			Hint:     "Lock table exhausted - typically caused by large objects (BLOBs) during restore",
+			Action:   "Option 1: Increase max_locks_per_transaction to 1024+ in postgresql.conf (requires restart). Option 2: Update dbbackup and retry - phased restore now auto-enabled for BLOB databases",
 			Severity: 2,
 		}
 	case "permission_denied":
@@ -142,8 +142,8 @@ func ClassifyError(errorMsg string) *ErrorClassification {
 			Type:     "critical",
 			Category: "locks",
 			Message:  errorMsg,
-			Hint:     "Lock table exhausted - typically caused by large objects in parallel restore",
-			Action:   "Increase max_locks_per_transaction in postgresql.conf to 512 or higher",
+			Hint:     "Lock table exhausted - typically caused by large objects (BLOBs) during restore",
+			Action:   "Option 1: Increase max_locks_per_transaction to 1024+ in postgresql.conf (requires restart). Option 2: Update dbbackup and retry - phased restore now auto-enabled for BLOB databases",
 			Severity: 2,
 		}
 	}