docs: add clawdis cron skill

skills/clawdis-cron/SKILL.md

@@ -0,0 +1,77 @@
+---
+name: clawdis-cron
+description: Schedule jobs and wakeups via Clawdis Gateway cron.* RPC.
+metadata: {"clawdis":{"always":true}}
+---
+
+# Clawdis Cron
+
+Cron runs inside the Gateway. Jobs live in `~/.clawdis/cron/jobs.json` and run logs in `~/.clawdis/cron/runs/<jobId>.jsonl`.
+
+Enable/disable
+- Enabled by default.
+- Disable with config `cron.enabled=false` or env `CLAWDIS_SKIP_CRON=1`.
+- Config: `cron.store`, `cron.maxConcurrentRuns`.
+
+RPC methods (Gateway WS)
+- `cron.list`, `cron.status`, `cron.add`, `cron.update`, `cron.remove`, `cron.run`, `cron.runs`
+- `wake` (enqueue system event + optionally trigger immediate heartbeat)
+
+Payload rules
+- `sessionTarget: "main"` requires `payload.kind: "systemEvent"`.
+- `sessionTarget: "isolated"` requires `payload.kind: "agentTurn"`.
+
+Examples
+
+One-shot reminder (main session, immediate wake):
+```json
+{
+  "method": "cron.add",
+  "params": {
+    "name": "remind-me",
+    "enabled": true,
+    "schedule": { "kind": "at", "atMs": 1734715200000 },
+    "sessionTarget": "main",
+    "wakeMode": "now",
+    "payload": { "kind": "systemEvent", "text": "Remind me in 20 minutes." }
+  }
+}
+```
+
+Recurring hourly check (isolated job, no external delivery):
+```json
+{
+  "method": "cron.add",
+  "params": {
+    "name": "hourly-check",
+    "enabled": true,
+    "schedule": { "kind": "every", "everyMs": 3600000 },
+    "sessionTarget": "isolated",
+    "wakeMode": "now",
+    "payload": { "kind": "agentTurn", "message": "Check battery; report only if < 20%.", "deliver": false },
+    "isolation": { "postToMainPrefix": "Cron" }
+  }
+}
+```
+
+Cron expression (weekday 07:30):
+```json
+{
+  "method": "cron.add",
+  "params": {
+    "name": "weekday-wakeup",
+    "enabled": true,
+    "schedule": { "kind": "cron", "expr": "30 7 * * 1-5", "tz": "America/Los_Angeles" },
+    "sessionTarget": "isolated",
+    "wakeMode": "now",
+    "payload": { "kind": "agentTurn", "message": "Wake me up and start music.", "deliver": true, "channel": "whatsapp" }
+  }
+}
+```
+
+Run history
+- `cron.runs` returns recent JSONL entries for a job.
+
+Notes
+- `wakeMode: "now"` triggers an immediate heartbeat for main jobs.
+- Isolated jobs run in `cron:<jobId>` sessions and post a summary back to main.