fix: Run Now agent-run timing + non-404 webview placeholder

Two independent fixes that both blocked the "install → Run Now → see
the Site tab render" loop.

1. CronViewModel.runNow stopped blocking on `cron tick`. Previously
   the UI waited up to 60 s on the tick before deciding whether the
   job succeeded, so any agent run that did real work (an LLM call +
   a few HTTP GETs + a file write = easily 90 s+) surfaced a false
   "Run failed" toast while the job kept running in the background.
   Dashboard updates landed minutes later, confusing the user.

   New shape: show "Agent started — dashboard will update when it
   finishes" the instant `cron run` queues the job, then call `cron
   tick` with a 300 s timeout to force execution. Tick failures are
   logged but don't overwrite the started-toast — HermesFileWatcher
   picks up the dashboard.json rewrite automatically when the agent
   finishes.

2. site-status-checker's webview widget pointed at
   `github.com/awizemann/scarf/tree/main/templates/awizemann/...`.
   The templates/ path only exists on project-sharing, not main, so
   GitHub returned 404 in the Site tab until the first cron run
   replaced the URL with the user's configured site. Switched the
   placeholder to `awizemann.github.io/scarf/` which always renders.

Bundle + catalog rebuilt against the updated dashboard.json.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

templates/catalog.json

@@ -7,8 +7,8 @@
         "name": "Alan Wizemann",
         "url": "https://github.com/awizemann/scarf"
       },
-      "bundleSha256": "2a4e0aba5bd4d86be3153d87c6ce219b9068223daebfad6f9db2b82c3752fac5",
-      "bundleSize": 7583,
+      "bundleSha256": "0a20802a8830a7cfdd1afa2888e42e113c9a17a37439384a3037d32ad1f24c1f",
+      "bundleSize": 7569,
       "category": "monitoring",
       "config": {
         "modelRecommendation": {