feat: add Slack integration package with Bolt framework

packages/slack/README.md

@@ -0,0 +1,27 @@
+# @opencode-ai/slack
+
+Slack bot integration for opencode that creates threaded conversations.
+
+## Setup
+
+1. Create a Slack app at https://api.slack.com/apps
+2. Enable Socket Mode
+3. Add the following OAuth scopes:
+   - `chat:write`
+   - `app_mentions:read`
+   - `channels:history`
+   - `groups:history`
+4. Install the app to your workspace
+5. Set environment variables in `.env`:
+   - `SLACK_BOT_TOKEN` - Bot User OAuth Token
+   - `SLACK_SIGNING_SECRET` - Signing Secret from Basic Information
+   - `SLACK_APP_TOKEN` - App-Level Token from Basic Information
+
+## Usage
+
+```bash
+# Edit .env with your Slack app credentials
+bun dev
+```
+
+The bot will respond to messages in channels where it's added, creating separate opencode sessions for each thread.