Add MCP delegation bridge and diagram tools

**Features Added**:

1. **Agent Registry (agent_registry.py)**
   - Thread-safe global singleton for MCP tool access to Agent instance
   - Enables MCP tools to call Agent.delegate() without circular imports
   - Registered at bot startup in bot_runner.py

2. **Sub-Agent Manager (sub_agent_manager.py)**
   - Watchdog system monitoring sub-agent lifecycle
   - Detects hung agents (5min timeout, 30s check interval)
   - Auto-cleanup and status tracking

3. **delegate_task MCP Tool (mcp_tools.py)**
   - Exposes Agent.delegate() to Claude via MCP protocol
   - Enables parallel sub-agent execution via tool calls
   - Supports specialist prompts and agent ID caching

4. **Memory Write Locks (memory_system.py)**
   - Thread-safe writes to prevent file corruption
   - Protects write_memory(), update_soul(), update_user()

5. **Diagram Tools**
   - Mermaid MCP server (flowcharts, sequence diagrams, etc.)
   - Excalidraw MCP server (hand-drawn style diagrams)
   - Config files in config/ directory

6. **Adapter Improvements**
   - Enhanced error handling across all adapters
   - Unified logging patterns

**Testing**: Ready for parallel sub-agent testing

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

adapters/runtime.py

@@ -98,6 +98,61 @@ class AdapterRuntime:
             print("[Runtime] Warning: No event loop for message dispatch")
             self._message_queue.put_nowait(message)
 
+    async def _detect_and_send_diagrams(
+        self,
+        response: str,
+        adapter: BaseAdapter,
+        channel_id: str,
+        thread_id: Optional[str]
+    ) -> None:
+        """Detect diagram file paths in response and auto-send them.
+
+        Args:
+            response: Agent's text response
+            adapter: Platform adapter to send files with
+            channel_id: Channel/chat ID
+            thread_id: Thread/message ID for replies
+        """
+        import re
+        from pathlib import Path
+
+        # Match diagram file paths: "Saved to: path/to/diagram.png"
+        # Pattern matches common phrases followed by file path with image/diagram extensions
+        pattern = r"(?:Saved|Created|Generated|Exported|File saved|Output file)\s*(?:to|at)?[:\s]+([^\s]+\.(?:png|svg|pdf|jpg|jpeg))"
+        matches = re.findall(pattern, response, re.IGNORECASE)
+
+        if not matches:
+            return
+
+        sent_files = []
+        for file_path_str in matches:
+            try:
+                file_path = Path(file_path_str)
+
+                # Check if file exists
+                if not file_path.exists():
+                    print(f"[Runtime] Diagram file not found: {file_path}")
+                    continue
+
+                # Send file via adapter
+                result = await adapter.send_file(
+                    channel_id=channel_id,
+                    file_path=str(file_path.absolute()),
+                    caption=f"Diagram: {file_path.name}",
+                    thread_id=thread_id,
+                )
+
+                if result.get("success"):
+                    sent_files.append(file_path.name)
+                    print(f"[Runtime] Sent diagram file: {file_path.name}")
+                else:
+                    print(f"[Runtime] Failed to send diagram: {result.get('error')}")
+            except Exception as e:
+                print(f"[Runtime] Error sending diagram file: {e}")
+
+        if sent_files:
+            print(f"[Runtime] Successfully sent {len(sent_files)} diagram file(s)")
+
     async def _process_message_queue(self) -> None:
         """Background task to process incoming messages."""
         print("[Runtime] Message processing loop started")
@@ -169,12 +224,22 @@ class AdapterRuntime:
                 user_message=processed_message.text,
                 username=username,
                 progress_callback=progress_callback,
+                inbound_message=processed_message,
             )
 
             # Apply postprocessors
             for postprocessor in self._postprocessors:
                 response = postprocessor(response, processed_message)
 
+            # NEW: Detect and send diagram files mentioned in response
+            if adapter:
+                await self._detect_and_send_diagrams(
+                    response,
+                    adapter,
+                    message.channel_id,
+                    message.thread_id,
+                )
+
             # Send response back
             if adapter:
                 reply_to = (