feat(desktop): make cron jobs the first-class sidebar entity

Redesign the cron surface around jobs (not run sessions), following
power-user patterns (GitHub Actions / Airflow / Dagu): master → detail → output.

Sidebar "Cron jobs" section:
- jobs with a state pip + live next-run countdown
- click toggles an inline run-history peek; a run opens its chat (active run highlighted)
- hover: trigger-now + manage (open the Cron page)
- capped at 50 with a "50+" badge

Cron page: de-nested from a collapse-in-row accordion to master/detail —
job list + the selected job's schedule, actions, and run history.

Backend: GET /api/cron/jobs/{id}/runs lists a job's run sessions.

Share STATE_DOT/jobState across both surfaces; drop dead code/keys.

hermes_cli/web_server.py

@@ -5650,6 +5650,53 @@ async def get_cron_job(job_id: str, profile: Optional[str] = None):
     return job
 
 
+@app.get("/api/cron/jobs/{job_id}/runs")
+async def list_cron_job_runs(job_id: str, profile: Optional[str] = None, limit: int = 20):
+    """Run sessions produced by a cron job, newest first.
+
+    Cron runs are stored as ordinary sessions whose id is
+    ``cron_{job_id}_{timestamp}`` (see cron/scheduler.run_job). A job's history
+    is therefore every session whose id carries that prefix; ``source='cron'``
+    narrows it and the id substring binds it to this job. Powers the run-history
+    list under each job in the desktop cron detail. Same row shape as
+    ``/api/sessions`` so the frontend can reuse SessionInfo.
+    """
+    selected = profile or _find_cron_job_profile(job_id)
+    # job_id may be a human name; resolve to the canonical id used in run-session ids.
+    canonical = job_id
+    if selected:
+        job = _call_cron_for_profile(selected, "get_job", job_id)
+        if job and job.get("id"):
+            canonical = str(job["id"])
+
+    try:
+        limit_n = max(1, min(int(limit), 100))
+    except (TypeError, ValueError):
+        limit_n = 20
+
+    db = _open_session_db_for_profile(selected)
+    try:
+        runs = db.list_sessions_rich(
+            source="cron",
+            id_query=f"cron_{canonical}_",
+            limit=limit_n,
+            offset=0,
+            order_by_last_active=True,
+        )
+        now = time.time()
+        for s in runs:
+            s["is_active"] = (
+                s.get("ended_at") is None
+                and (now - s.get("last_active", s.get("started_at", 0))) < 300
+            )
+            s["archived"] = bool(s.get("archived"))
+            if selected:
+                s["profile"] = selected
+        return {"runs": runs, "limit": limit_n}
+    finally:
+        db.close()
+
+
 @app.post("/api/cron/jobs")
 async def create_cron_job(body: CronJobCreate, profile: str = "default"):
     try: