Migrate to Claude Agent SDK framework (v0.2.0)

BREAKING CHANGE: Replaced FastAPI server wrapper with direct Claude Agent SDK integration

## Major Changes

### Architecture
- **OLD:** Bot → FastAPI Server → claude-code-sdk → Claude
- **NEW:** Bot → Claude Agent SDK → Claude (Pro subscription OR API)
- Eliminated HTTP server overhead
- Single-process architecture

### LLM Backend (llm_interface.py)
- Implemented Claude Agent SDK as DEFAULT mode
- Added three-mode architecture:
  - agent-sdk (default) - Uses Pro subscription
  - direct-api - Pay-per-token Anthropic API
  - legacy-server - Backward compat with old setup
- Created async/sync bridge using anyio
- Preserved all existing functionality (17 tools, memory, scheduling)

### Dependencies (requirements.txt)
- Replaced: claude-code-sdk → claude-agent-sdk>=0.1.0
- Added: anyio>=4.0.0 for async bridging
- Removed: fastapi, uvicorn (no longer needed for default mode)

### New Files
- ajarbot.py - Unified launcher with pre-flight checks
- run.bat - Windows one-command launcher (auto-setup)
- pyproject.toml - Python package metadata
- MIGRATION.md - Upgrade guide from old setup
- AGENT_SDK_IMPLEMENTATION.md - Technical documentation
- QUICK_REFERENCE_AGENT_SDK.md - Quick reference card
- test_agent_sdk.py - Comprehensive test suite

### Updated Documentation
- CLAUDE_CODE_SETUP.md - Rewritten for Agent SDK
- README.md - Updated quick start for new default
- .env.example - Added AJARBOT_LLM_MODE configuration

### Deleted Files
- claude_code_server.py - Replaced by agent-sdk integration
- heartbeat.py - Superseded by scheduled_tasks.py
- pulse_brain.py - Unused in production

## Migration Path

Old setup:
1. Start FastAPI server: python claude_code_server.py
2. Start bot: python bot_runner.py
3. Set USE_CLAUDE_CODE_SERVER=true

New setup:
1. Run: run.bat (or python ajarbot.py)
   - That's it! Single command.

## Benefits

✅ Zero API costs (uses Claude Pro subscription)
✅ Simplified deployment (no separate server)
✅ Single-command launch (run.bat)
✅ Faster response times (no HTTP overhead)
✅ All functionality preserved (17 tools, memory, adapters)
✅ Backward compatible (old env vars still work)

## Compatibility

- Python 3.10+ required
- Node.js required (for Claude Code CLI bundled with SDK)
- Windows 11 tested and optimized
- All existing tools, memory system, and adapters unchanged

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

.env.example

@@ -1,8 +1,55 @@
-# Environment Variables (EXAMPLE)
-# Copy this to .env and add your actual API keys
+# ========================================
+# Ajarbot Environment Configuration
+# ========================================
+# Copy this file to .env and configure for your setup
 
-# Anthropic API Key - Get from https://console.anthropic.com/settings/keys
+# ========================================
+# LLM Configuration
+# ========================================
+
+# LLM Mode - Choose how to access Claude
+# Options:
+#   - "agent-sdk" (default) - Use Claude Pro subscription via Agent SDK
+#   - "api"                 - Use pay-per-token API (requires ANTHROPIC_API_KEY)
+#
+# Agent SDK mode pros: Unlimited usage within Pro limits, no API key needed
+# API mode pros: Works in any environment, predictable costs, better for production
+AJARBOT_LLM_MODE=agent-sdk
+
+# Anthropic API Key - ONLY required for "api" mode
+# Get your key from: https://console.anthropic.com/settings/keys
+# For agent-sdk mode, authenticate with: claude auth login
 ANTHROPIC_API_KEY=your-api-key-here
 
-# Optional: GLM API Key (if using GLM provider)
+# ========================================
+# Messaging Platform Adapters
+# ========================================
+# Adapter credentials can also be stored in config/adapters.local.yaml
+
+# Slack
+# Get tokens from: https://api.slack.com/apps
+AJARBOT_SLACK_BOT_TOKEN=xoxb-your-bot-token
+AJARBOT_SLACK_APP_TOKEN=xapp-your-app-token
+
+# Telegram
+# Get token from: https://t.me/BotFather
+AJARBOT_TELEGRAM_BOT_TOKEN=123456:ABC-your-bot-token
+
+# ========================================
+# Alternative LLM Providers (Optional)
+# ========================================
+
+# GLM (z.ai) - Optional alternative to Claude
 # GLM_API_KEY=your-glm-key-here
+
+# ========================================
+# Legacy/Deprecated Settings
+# ========================================
+# The following settings are deprecated and no longer needed:
+#
+# USE_CLAUDE_CODE_SERVER=true
+# CLAUDE_CODE_SERVER_URL=http://localhost:8000
+# USE_AGENT_SDK=true
+# USE_DIRECT_API=true
+#
+# Use AJARBOT_LLM_MODE instead (see above)