Implement working Mastodon bot with proposal system

Major Features:
- Mastodon integration with polling-based listener (streaming unreliable)
- Claude AI integration via llm CLI with API key support
- Public proposal announcements with voting
- Markdown stripping for Mastodon plain text
- Thread-aware voting system

Configuration:
- Added requirements.txt with all dependencies
- API key configuration in config.yaml (not streamed keys)
- Support for multiple Claude models via llm-anthropic

Platform Adapter (Mastodon):
- Polling notifications every 5 seconds (more reliable than streaming)
- Notification ID tracking to prevent re-processing on restart
- Markdown stripping for clean plain text output
- Vote thread matching via announcement IDs

Agent & Governance:
- Conversational tone (direct, concise, not legalistic)
- Proposal creation with AI-generated titles and descriptions
- Public announcements for proposals with all details
- Vote casting with automatic proposal detection from threads
- Constitutional reasoning for governance decisions

Bot Features:
- Long message splitting into threaded posts
- Public proposal announcements separate from user replies
- Announcement includes: title, proposer, description, deadline, voting instructions
- Vote tracking linked to proposal announcement threads

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

requirements.txt

@@ -0,0 +1,17 @@
+# Core dependencies
+Mastodon.py>=1.8.0
+SQLAlchemy>=2.0.0
+llm>=0.13.0
+llm-anthropic>=0.23
+
+# Configuration and validation
+pydantic>=2.0.0
+pydantic-settings>=2.0.0
+PyYAML>=6.0
+
+# Database
+alembic>=1.12.0
+
+# Utilities
+python-dateutil>=2.8.0
+markdown>=3.10