ghostclaw: Skill for Claude Code

Add Heartbeat

Adds a periodic heartbeat that wakes the agent on a cron schedule, runs through a checklist of cheap checks, and only messages the user if something needs attention.

What it does

1. Creates groups/main/HEARTBEAT.md with a template checklist
2. Registers a scheduled task that runs the heartbeat on a cron (default: every 30 minutes)
3. The agent reads the checklist, runs each check, and stays silent if everything is fine

Setup

1. Create HEARTBEAT.md (if not exists)

Check if groups/main/HEARTBEAT.md exists. If not, create it with this template:

# Heartbeat Checks

Run these checks silently. Only message the user if something actually needs their attention.

## Checks

### 1. Error Log

\`\`\`bash
tail -20 ~/nanoclaw/logs/errors.log
\`\`\`

- Each line is JSON with a `"time"` field (Unix ms).
- Calculate cutoff: `Date.now() - (35 * 60 * 1000)`.
- **Ignore** any entry where `time < cutoff`. Don't mention ignored entries at all.
- If the file is empty or all entries are old, this check passes silently.
- If recent errors exist, summarise the actual problem in one line.

### 2. Runaway Processes

\`\`\`bash
ps aux -r | head -5
\`\`\`

- Check if any process is using >90% CPU.
- Chrome/agent-browser processes that have been running for hours are zombies — kill them:
  \`\`\`bash
  pkill -9 -f "agent-browser-chrome"
  \`\`\`
- Alert the user: "Killed zombie Chrome process (was using X% CPU)."
- Also check load average (`uptime`). If load >4, mention it.

### 3. Disk Space

\`\`\`bash
df -h /
\`\`\`

- Alert if usage >80%. State the percentage and partition.

## Rules

- **Silent by default.** If everything is fine: `<internal>All checks passed</internal>` — nothing else.
- **Never explain your reasoning.** Just do the checks and report problems.
- **Never report old/filtered entries.** If an entry is too old, pretend it doesn't exist.
- When alerting, state the problem in plain English, one or two lines max.
- Don't repeat alerts already visible in recent conversation history.