Add sub-agent orchestration, MCP tools, and critical bug fixes

Major Features:
- Sub-agent orchestration system with dynamic specialist spawning
  * spawn_sub_agent(): Create specialists with custom prompts
  * delegate(): Convenience method for task delegation
  * Cached specialists for reuse
  * Separate conversation histories and focused context

- MCP (Model Context Protocol) tool integration
  * Zettelkasten: fleeting_note, daily_note, permanent_note, literature_note
  * Search: search_vault (hybrid search), search_by_tags
  * Web: web_fetch for real-time data
  * Zero-cost file/system operations on Pro subscription

Critical Bug Fixes:
- Fixed max tool iterations (15 → 30, configurable)
- Fixed max_tokens error in Agent SDK query() call
- Fixed MCP tool routing in execute_tool()
  * Routes zettelkasten + web tools to async handlers
  * Prevents "Unknown tool" errors

Documentation:
- SUB_AGENTS.md: Complete guide to sub-agent system
- MCP_MIGRATION.md: Agent SDK migration details
- SOUL.example.md: Sanitized bot identity template
- scheduled_tasks.example.yaml: Sanitized task config template

Security:
- Added obsidian vault to .gitignore
- Protected SOUL.md and MEMORY.md (personal configs)
- Sanitized example configs with placeholders

Dependencies:
- Added beautifulsoup4, httpx, lxml for web scraping
- Updated requirements.txt

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

tools.py

@@ -342,7 +342,47 @@ TOOL_DEFINITIONS = [
 def execute_tool(tool_name: str, tool_input: Dict[str, Any], healing_system: Any = None) -> str:
     """Execute a tool and return the result as a string."""
     try:
-        # File tools
+        # MCP tools (zettelkasten + web_fetch) - route to mcp_tools.py
+        MCP_TOOLS = {
+            "web_fetch", "fleeting_note", "daily_note", "literature_note",
+            "permanent_note", "search_vault", "search_by_tags"
+        }
+
+        if tool_name in MCP_TOOLS:
+            # Route to MCP tool handlers
+            import anyio
+            from mcp_tools import (
+                web_fetch_tool, fleeting_note_tool, daily_note_tool,
+                literature_note_tool, permanent_note_tool,
+                search_vault_tool, search_by_tags_tool
+            )
+
+            # Map tool names to their handlers
+            mcp_handlers = {
+                "web_fetch": web_fetch_tool,
+                "fleeting_note": fleeting_note_tool,
+                "daily_note": daily_note_tool,
+                "literature_note": literature_note_tool,
+                "permanent_note": permanent_note_tool,
+                "search_vault": search_vault_tool,
+                "search_by_tags": search_by_tags_tool,
+            }
+
+            # Execute MCP tool asynchronously
+            handler = mcp_handlers[tool_name]
+            result = anyio.run(handler, tool_input)
+
+            # Convert result to string if needed
+            if isinstance(result, dict):
+                if "error" in result:
+                    return f"Error: {result['error']}"
+                elif "content" in result:
+                    return result["content"]
+                else:
+                    return str(result)
+            return str(result)
+
+        # File tools (traditional handlers - kept for backward compatibility)
         if tool_name == "read_file":
             return _read_file(tool_input["file_path"])
         elif tool_name == "write_file":