improve gmail sync: email input, permanent errors, auto-dock

- add isync to setup.sh
- ask for gmail address alongside app password in integrations
- add PermanentError to job queue (skips retries for non-recoverable failures)
- use PermanentError for missing credentials, missing executable, auth failures
- auto-add /email to dock after successful gmail sync
- invalidate dock cache on sync completion for seamless UI update

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

src/servers/queue/index.ts

@@ -5,7 +5,17 @@ import './handlers';
 export { enqueue, cancelJob } from './engine';
 export { readJob, listAllJobs } from './storage';
 export { registerHandler } from './handler-registry';
-export type { Job, JobStep, JobStatus, JobProgress, StepContext, JobHandler, JobHandlerStep, EnqueueParams } from './types';
+export { PermanentError } from './types';
+export type {
+  Job,
+  JobStep,
+  JobStatus,
+  JobProgress,
+  StepContext,
+  JobHandler,
+  JobHandlerStep,
+  EnqueueParams,
+} from './types';
 
 export async function initQueue() {
   await ensureQueueDir();