fix(cron): fix timeout, add timestamp validation, enable file sync

Fixes #7667

Task 1: Fix cron operation timeouts
- Increase default gateway tool timeout from 10s to 30s
- Increase cron-specific tool timeout to 60s
- Increase CLI default timeout from 10s to 30s
- Prevents timeouts when gateway is busy with long-running jobs

Task 2: Add timestamp validation
- New validateScheduleTimestamp() function in validate-timestamp.ts
- Rejects atMs timestamps more than 1 minute in the past
- Rejects atMs timestamps more than 10 years in the future
- Applied to both cron.add and cron.update operations
- Provides helpful error messages with current time and offset

Task 3: Enable file sync for manual edits
- Track file modification time (storeFileMtimeMs) in CronServiceState
- Check file mtime in ensureLoaded() and reload if changed
- Recompute next runs after reload to maintain accuracy
- Update mtime after persist() to prevent reload loop
- Dashboard now picks up manual edits to ~/.openclaw/cron/jobs.json

src/agents/tools/gateway.ts

@@ -22,7 +22,7 @@ export function resolveGatewayOptions(opts?: GatewayCallOptions) {
   const timeoutMs =
     typeof opts?.timeoutMs === "number" && Number.isFinite(opts.timeoutMs)
       ? Math.max(1, Math.floor(opts.timeoutMs))
-      : 10_000;
+      : 30_000;
   return { url, token, timeoutMs };
 }