Implement self-healing system Phase 1: Error capture and logging

- Add SelfHealingSystem with error observation infrastructure
- Capture errors with full context: type, message, stack trace, intent, inputs
- Log to MEMORY.md with deduplication (max 3 attempts per error signature)
- Integrate error capture in agent, tools, runtime, and scheduler
- Non-invasive: preserves all existing error handling behavior
- Foundation for future diagnosis and auto-fixing capabilities

Phase 1 of 4-phase rollout - observation only, no auto-fixing yet.

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

tools.py

@@ -324,7 +324,7 @@ TOOL_DEFINITIONS = [
 ]
 
 
-def execute_tool(tool_name: str, tool_input: Dict[str, Any]) -> str:
+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
@@ -407,6 +407,13 @@ def execute_tool(tool_name: str, tool_input: Dict[str, Any]) -> str:
         else:
             return f"Error: Unknown tool '{tool_name}'"
     except Exception as e:
+        if healing_system:
+            healing_system.capture_error(
+                error=e,
+                component=f"tools.py:{tool_name}",
+                intent=f"Executing {tool_name} tool",
+                context={"tool_name": tool_name, "input": tool_input},
+            )
         return f"Error executing {tool_name}: {str(e)}"