fix(query): add timeout settings entry to error page

apps/desktop/src/lib/__tests__/sql/queryError.spec.ts

@@ -1,5 +1,43 @@
 import { describe, expect, it } from "vitest";
-import { isQueryTimeoutErrorMessage } from "@/lib/sql/queryError";
+import { isConnectionTimeoutErrorMessage, isQueryTimeoutErrorMessage } from "@/lib/sql/queryError";
+
+describe("isConnectionTimeoutErrorMessage", () => {
+  it("detects connection creation and handshake timeouts", () => {
+    expect(isConnectionTimeoutErrorMessage("PostgreSQL connection failed: Timeout occurred while creating a new object")).toBe(true);
+    expect(isConnectionTimeoutErrorMessage("MySQL connection failed: TLS handshake timed out after 10 seconds")).toBe(true);
+    expect(isConnectionTimeoutErrorMessage("The connection attempt timed out")).toBe(true);
+  });
+
+  it("detects structured connect-stage timeouts", () => {
+    const timeoutError = {
+      version: 1,
+      code: "DBX-JDBC-2001",
+      messageKey: "backendErrors.jdbc.operationTimedOut",
+      messageParams: { stage: "connect" },
+      source: "jdbcAgent",
+      operationOutcome: "not_started" as const,
+    } as const;
+
+    expect(isConnectionTimeoutErrorMessage("Database operation timed out (stage: connect).", timeoutError)).toBe(true);
+  });
+
+  it("does not classify query, pool checkout, cancellation, or syntax errors as connection timeouts", () => {
+    expect(isConnectionTimeoutErrorMessage("Query timed out after 30 seconds")).toBe(false);
+    expect(isConnectionTimeoutErrorMessage("PostgreSQL connection pool checkout timed out (5s)")).toBe(false);
+    expect(isConnectionTimeoutErrorMessage("Cancel request timed out after 10s.")).toBe(false);
+    expect(isConnectionTimeoutErrorMessage('syntax error at or near "select"')).toBe(false);
+    expect(
+      isConnectionTimeoutErrorMessage("Database operation timed out (stage: execute).", {
+        version: 1,
+        code: "DBX-JDBC-2002",
+        messageKey: "backendErrors.jdbc.operationTimedOut",
+        messageParams: { stage: "execute" },
+        source: "jdbcAgent",
+        operationOutcome: "unknown",
+      }),
+    ).toBe(false);
+  });
+});
 
 describe("isQueryTimeoutErrorMessage", () => {
   it("detects DBX query timeout messages", () => {

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

@@ -1,6 +1,20 @@
 import type { BackendError } from "@/lib/backend/errorUtils";
 
 const QUERY_TIMEOUT_STAGES = new Set(["execute", "fetch"]);
+const CONNECTION_TIMEOUT_STAGES = new Set(["connect", "connection"]);
+
+export function isConnectionTimeoutErrorMessage(message: string, backendError?: BackendError): boolean {
+  if (backendError?.messageKey === "backendErrors.jdbc.operationTimedOut") {
+    const stage = String(backendError.messageParams.stage ?? "").toLowerCase();
+    return CONNECTION_TIMEOUT_STAGES.has(stage);
+  }
+
+  const lower = message.toLowerCase();
+  if (/\btimeout occurred while creating a new object\b/.test(lower)) return true;
+  if (/\b(?:pool\s+checkout|checkout|metadata|loading|health check|cancel request)\b/.test(lower)) return false;
+  if (/\b(?:connection|connect|handshake)\b[\s\S]{0,80}\b(?:timed out|timeout expired|timeout exceeded|time-out)\b/.test(lower)) return true;
+  return /\b(?:timed out|timeout expired|timeout exceeded|time-out)\b[\s\S]{0,80}\b(?:connection attempt|connect|handshake)\b/.test(lower);
+}
 
 export function isQueryTimeoutErrorMessage(message: string, backendError?: BackendError): boolean {
   if (backendError?.messageKey === "backendErrors.jdbc.operationTimedOut") {