Feature: Observability and metrics

[LBC970]

Description

Add visibility into bot health and participation trends.

Features

1. Metrics/stats dashboard

Track participation trends over time:

• Signup counts per week
• Pairing completion rates
• Badge progression stats
• Most/least paired individuals

Could be a /coffee-admin stats command or a weekly summary.

2. Slack notifications for errors

Alert admins when something fails:

• Failed pairing runs
• S3 read/write errors
• Slack API failures
• Missing environment variables

Options:

• DM the admin user(s)
• Post to a dedicated #coffee-bot-alerts channel
• Or just improve CloudWatch logging/alarms

3. Structured logging

Currently uses print statements. Consider:

• JSON-formatted logs for easier CloudWatch parsing
• Log levels (INFO, WARNING, ERROR)
• Request tracing (correlation IDs)

Example Stats Output

Coffee Bot Stats (Last 30 Days)

Participation:
- Average signups per week: 12
- Total unique participants: 24
- Most active: Alice (8 weeks), Bob (7 weeks)

Pairings:
- Total pairings made: 42
- Singles: 6

Badge Distribution:
🏆 Coffee Legend: 2
🏅 Coffee Veteran: 4
⭐ Coffee Enthusiast: 6
🥈 Regular: 8
🥉 Coffee Newbie: 3
☕ First Timer: 1