Initial commit - LettaBot multi-channel AI assistant

Co-authored-by: Cameron Pfiffer <cameron@pfiffer.org>
Co-authored-by: Caren Thomas <carenthomas@gmail.com>
Co-authored-by: Charles Packer <packercharles@gmail.com>
Co-authored-by: Sarah Wooders <sarahwooders@gmail.com>

.skills/cron/SKILL.md

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+---
+name: cron
+description: Create and manage scheduled tasks (cron jobs) that send you messages at specified times.
+---
+
+# Cron Jobs
+
+Schedule tasks that send you messages at specified times. Jobs are scheduled immediately when created.
+
+## Quick Reference
+
+```bash
+lettabot-cron list                    # List all jobs
+lettabot-cron create [options]        # Create job
+lettabot-cron delete ID               # Delete job
+lettabot-cron enable ID               # Enable job
+lettabot-cron disable ID              # Disable job
+```
+
+## Create a Job
+
+```bash
+lettabot-cron create \
+  --name "Morning Briefing" \
+  --schedule "0 8 * * *" \
+  --message "Good morning! Review tasks for today." \
+  --deliver telegram:123456789
+```
+
+**Options:**
+- `-n, --name` - Job name (required)
+- `-s, --schedule` - Cron expression (required)  
+- `-m, --message` - Message sent to you when job runs (required)
+- `-d, --deliver` - Where to send response (format: `channel:chatId`). **Defaults to last messaged chat.**
+- `--disabled` - Create disabled
+
+## Message Format
+
+When a cron job runs, you receive a message like:
+
+```
+[cron:cron-123abc Morning Briefing] Good morning! Review tasks for today.
+Current time: 1/27/2026, 8:00:00 AM (America/Los_Angeles)
+```
+
+This tells you:
+- The message came from a cron job (not a user)
+- The job ID and name
+- The current time
+
+## Cron Schedule Syntax
+
+```
+┌───────── minute (0-59)
+│ ┌─────── hour (0-23)  
+│ │ ┌───── day of month (1-31)
+│ │ │ ┌─── month (1-12)
+│ │ │ │ ┌─ day of week (0-6, Sun=0)
+* * * * *
+```
+
+| Pattern | When |
+|---------|------|
+| `0 8 * * *` | Daily at 8:00 AM |
+| `0 9 * * 1-5` | Weekdays at 9:00 AM |
+| `0 */2 * * *` | Every 2 hours |
+| `30 17 * * 5` | Fridays at 5:30 PM |
+| `0 0 1 * *` | First of month at midnight |
+
+## Examples
+
+**Daily morning check-in (delivered to Telegram):**
+```bash
+lettabot-cron create \
+  -n "Morning" \
+  -s "0 8 * * *" \
+  -m "Good morning! What's on today's agenda?" \
+  -d telegram:123456789
+```
+
+**Weekly review (delivered to Slack):**
+```bash
+lettabot-cron create \
+  -n "Weekly Review" \
+  -s "0 17 * * 5" \
+  -m "Friday wrap-up: What did we accomplish?" \
+  -d slack:C1234567890
+```
+
+## Notes
+
+- Jobs schedule immediately when created (no restart needed)
+- Use `lettabot-cron list` to see next run times and last run status
+- Jobs persist in `cron-jobs.json`
+- Logs written to `cron-log.jsonl`