fix(postgres): correct query and connection timeout handling under SSH tunnel

apps/desktop/src/lib/sql/queryTimeout.ts

@@ -1,8 +1,12 @@
 import { splitSqlStatementRanges } from "@/lib/sql/sqlStatementRanges";
+import { tokenizeSqlSemantic } from "@/lib/sql/semantic/tokens";
 import type { ConnectionConfig, DatabaseType } from "@/types/database";
 
 export const DEFAULT_QUERY_TIMEOUT_SECS = 60;
 
+const POSTGRES_ROW_STATEMENT_KEYWORDS = new Set(["select", "show", "explain", "table", "with"]);
+const POSTGRES_RETURNING_STATEMENT_KEYWORDS = new Set(["insert", "update", "delete", "merge"]);
+
 export function queryTimeoutSecsForConnection(connection?: Pick<ConnectionConfig, "query_timeout_secs"> | null): number {
   const value = Number(connection?.query_timeout_secs);
   return Number.isFinite(value) && value >= 0 ? value : DEFAULT_QUERY_TIMEOUT_SECS;
@@ -11,7 +15,24 @@ export function queryTimeoutSecsForConnection(connection?: Pick<ConnectionConfig
 export function frontendQueryTimeoutSecsForSql(sql: string, databaseType: DatabaseType | undefined, queryTimeoutSecs: number): number {
   if (queryTimeoutSecs === 0) return 0;
 
+  // PostgreSQL applies the configured timeout while the backend receives rows
+  // over a slow SSH tunnel. An absolute browser-side deadline can reject a
+  // successful, steadily progressing page fetch first, so let the backend own
+  // the timeout for row-returning PostgreSQL statements.
+  if (databaseType === "postgres" && postgresQueryMayReturnRows(sql, databaseType)) return 0;
+
   const baseTimeoutSecs = Math.max(queryTimeoutSecs * 2, 60);
   const statementCount = Math.max(splitSqlStatementRanges(sql, databaseType).length, 1);
   return baseTimeoutSecs * statementCount;
 }
+
+function postgresQueryMayReturnRows(sql: string, databaseType: DatabaseType): boolean {
+  return splitSqlStatementRanges(sql, databaseType).some(({ sql: statement }) => {
+    const tokens = tokenizeSqlSemantic(statement, "postgres");
+    const firstKeyword = tokens.find((token) => token.kind === "word" && token.depth === 0)?.normalized;
+    if (!firstKeyword) return false;
+    if (POSTGRES_ROW_STATEMENT_KEYWORDS.has(firstKeyword)) return true;
+    if (!POSTGRES_RETURNING_STATEMENT_KEYWORDS.has(firstKeyword)) return false;
+    return tokens.some((token) => token.kind === "word" && token.depth === 0 && token.normalized === "returning");
+  });
+}