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/cron-tool.ts

@@ -208,7 +208,7 @@ Use jobId as the canonical identifier; id is accepted for compatibility. Use con
       const gatewayOpts: GatewayCallOptions = {
         gatewayUrl: readStringParam(params, "gatewayUrl", { trim: false }),
         gatewayToken: readStringParam(params, "gatewayToken", { trim: false }),
-        timeoutMs: typeof params.timeoutMs === "number" ? params.timeoutMs : undefined,
+        timeoutMs: typeof params.timeoutMs === "number" ? params.timeoutMs : 60_000,
       };
 
       switch (action) {