[Plugin] Slack/Discord Bot — run diagnostics from chat

[francomano]

Description

A plugin that adds a Slack/Discord bot command interface. Run proxy diagnostics directly from chat by mentioning the bot.

Features

• Slash command: /proxydoctor diagnose https://example.com --proxy socks5://host:port
• Response as a rich embed (Discord) or blocks (Slack)
• Scheduled checks: /proxydoctor watch https://example.com every 5m
• Alert channel: send failures to a specific channel
• Thread-per-diagnosis for detailed results

Implementation

• Discord: discordgo library
• Slack: slack-go/slack library
• Uses MiddlewarePlugin to hook into diagnosis lifecycle
• Config via env vars: PROXYDOCTOR_DISCORD_TOKEN, PROXYDOCTOR_SLACK_TOKEN

Acceptance Criteria

• Bot responds to slash commands
• Diagnosis results displayed as rich embeds
• Scheduled monitoring posts results to channel
• Alerts sent on check failures
• Works with both Discord and Slack (separate configs)

[francomano]

Codebase starting point: see docs/ISSUE_STARTING_POINTS.md for the concrete files to start from for this issue.