feat(python): add zeroclaw-tools companion package for LangGraph tool calling

- Add Python package with LangGraph-based agent for consistent tool calling
- Provides reliable tool execution for providers with inconsistent native support
- Includes tools: shell, file_read, file_write, web_search, http_request, memory
- Discord bot integration included
- CLI tool for quick interactions
- Works with any OpenAI-compatible provider (Z.AI, OpenRouter, Groq, etc.)

Why: Some LLM providers (e.g., GLM-5/Zhipu) have inconsistent tool calling behavior.
LangGraph's structured approach guarantees reliable tool execution across all providers.

python/zeroclaw_tools/tools/file.py

@@ -0,0 +1,60 @@
+"""
+File read/write tools.
+"""
+
+import os
+
+from langchain_core.tools import tool
+
+
+MAX_FILE_SIZE = 100_000
+
+
+@tool
+def file_read(path: str) -> str:
+    """
+    Read the contents of a file at the given path.
+
+    Args:
+        path: The file path to read (absolute or relative)
+
+    Returns:
+        The file contents, or an error message
+    """
+    try:
+        with open(path, "r", encoding="utf-8", errors="replace") as f:
+            content = f.read()
+            if len(content) > MAX_FILE_SIZE:
+                return content[:MAX_FILE_SIZE] + f"\n... (truncated, {len(content)} bytes total)"
+            return content
+    except FileNotFoundError:
+        return f"Error: File not found: {path}"
+    except PermissionError:
+        return f"Error: Permission denied: {path}"
+    except Exception as e:
+        return f"Error: {e}"
+
+
+@tool
+def file_write(path: str, content: str) -> str:
+    """
+    Write content to a file, creating directories if needed.
+
+    Args:
+        path: The file path to write to
+        content: The content to write
+
+    Returns:
+        Success message or error
+    """
+    try:
+        parent = os.path.dirname(path)
+        if parent:
+            os.makedirs(parent, exist_ok=True)
+        with open(path, "w", encoding="utf-8") as f:
+            f.write(content)
+        return f"Successfully wrote {len(content)} bytes to {path}"
+    except PermissionError:
+        return f"Error: Permission denied: {path}"
+    except Exception as e:
+        return f"Error: {e}"