feat: fallback to ctid for editing tables without primary key

When a table has no PRIMARY KEY, use PostgreSQL's ctid (physical row ID)
to identify rows for UPDATE/DELETE operations instead of blocking edits.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/types/index.ts

@@ -30,6 +30,7 @@ export interface PaginatedQueryResult extends QueryResult {
   total_rows: number;
   page: number;
   page_size: number;
+  ctids: string[];
 }
 
 export interface SchemaObject {