feat(timeout): support global connection and query timeout settings

apps/desktop/src/lib/connection/timeoutInheritanceBackup.ts

@@ -0,0 +1,48 @@
+export const TIMEOUT_INHERITANCE_BACKUP_STORAGE_KEY = "dbx-timeout-inheritance-backup-v1";
+
+export interface TimeoutInheritanceBackup {
+  version: 1;
+  globalConnectTimeoutSecs: number;
+  globalQueryTimeoutSecs: number;
+  connectSnapshots: Record<string, number>;
+  querySnapshots: Record<string, number>;
+}
+
+function normalizeSnapshots(value: unknown, min: number): Record<string, number> {
+  if (!value || typeof value !== "object" || Array.isArray(value)) return {};
+  const snapshots: Record<string, number> = {};
+  for (const [id, timeout] of Object.entries(value)) {
+    if (!id.trim() || typeof timeout !== "number" || !Number.isFinite(timeout)) continue;
+    snapshots[id] = Math.min(300, Math.max(min, Math.round(timeout)));
+  }
+  return snapshots;
+}
+
+export function loadTimeoutInheritanceBackup(): TimeoutInheritanceBackup | null {
+  try {
+    const raw = localStorage.getItem(TIMEOUT_INHERITANCE_BACKUP_STORAGE_KEY);
+    if (!raw) return null;
+    const parsed = JSON.parse(raw) as Partial<TimeoutInheritanceBackup>;
+    if (parsed.version !== 1) return null;
+    const globalConnectTimeoutSecs = Number(parsed.globalConnectTimeoutSecs);
+    const globalQueryTimeoutSecs = Number(parsed.globalQueryTimeoutSecs);
+    if (!Number.isFinite(globalConnectTimeoutSecs) || !Number.isFinite(globalQueryTimeoutSecs)) return null;
+    return {
+      version: 1,
+      globalConnectTimeoutSecs: Math.min(300, Math.max(1, Math.round(globalConnectTimeoutSecs))),
+      globalQueryTimeoutSecs: Math.min(300, Math.max(0, Math.round(globalQueryTimeoutSecs))),
+      connectSnapshots: normalizeSnapshots(parsed.connectSnapshots, 1),
+      querySnapshots: normalizeSnapshots(parsed.querySnapshots, 0),
+    };
+  } catch {
+    return null;
+  }
+}
+
+export function saveTimeoutInheritanceBackup(backup: TimeoutInheritanceBackup): void {
+  try {
+    localStorage.setItem(TIMEOUT_INHERITANCE_BACKUP_STORAGE_KEY, JSON.stringify(backup));
+  } catch {
+    // Settings persistence remains the primary source when local storage is unavailable.
+  }
+}