Update README.MD and add nano-claude-code v3.0 + original-source-code/src

- README.MD: add original-source-code and nano-claude-code sections, update
  overview table (4 subprojects), add v3.0 news entry, expand comparison table
  with memory/multi-agent/skills dimensions
- nano-claude-code v3.0: multi-agent package (multi_agent/), memory package
  (memory/), skill package (skill/) with built-in /commit and /review skills,
  context compression (compaction.py), tool registry plugin system, diff view,
  17 slash commands, 18 built-in tools, 101 tests (~5000 lines total)
- original-source-code/src: add raw TypeScript source tree (1884 files)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nano-claude-code/tests/test_tool_registry.py

@@ -0,0 +1,160 @@
+from __future__ import annotations
+
+import pytest
+
+from tool_registry import (
+    ToolDef,
+    clear_registry,
+    execute_tool,
+    get_all_tools,
+    get_tool,
+    get_tool_schemas,
+    register_tool,
+)
+
+
+@pytest.fixture(autouse=True)
+def _clean_registry():
+    """Reset registry before each test."""
+    clear_registry()
+    yield
+    clear_registry()
+
+
+def _make_echo_tool(name: str = "echo", read_only: bool = False) -> ToolDef:
+    """Helper to build a simple echo tool."""
+    schema = {
+        "name": name,
+        "description": f"Echo tool ({name})",
+        "input_schema": {
+            "type": "object",
+            "properties": {
+                "text": {"type": "string", "description": "text to echo"},
+            },
+            "required": ["text"],
+        },
+    }
+
+    def func(params: dict, config: dict) -> str:
+        return params["text"]
+
+    return ToolDef(
+        name=name,
+        schema=schema,
+        func=func,
+        read_only=read_only,
+        concurrent_safe=True,
+    )
+
+
+# ------------------------------------------------------------------
+# register and get
+# ------------------------------------------------------------------
+
+def test_register_and_get():
+    tool = _make_echo_tool()
+    register_tool(tool)
+    result = get_tool("echo")
+    assert result is not None
+    assert result.name == "echo"
+
+
+def test_get_unknown_returns_none():
+    assert get_tool("no_such_tool") is None
+
+
+# ------------------------------------------------------------------
+# get_all_tools
+# ------------------------------------------------------------------
+
+def test_get_all_tools_empty():
+    assert get_all_tools() == []
+
+
+def test_get_all_tools():
+    register_tool(_make_echo_tool("a"))
+    register_tool(_make_echo_tool("b"))
+    names = [t.name for t in get_all_tools()]
+    assert sorted(names) == ["a", "b"]
+
+
+# ------------------------------------------------------------------
+# get_tool_schemas
+# ------------------------------------------------------------------
+
+def test_get_tool_schemas():
+    register_tool(_make_echo_tool("echo"))
+    schemas = get_tool_schemas()
+    assert len(schemas) == 1
+    assert schemas[0]["name"] == "echo"
+
+
+# ------------------------------------------------------------------
+# execute_tool
+# ------------------------------------------------------------------
+
+def test_execute_tool():
+    register_tool(_make_echo_tool())
+    result = execute_tool("echo", {"text": "hello"}, config={})
+    assert result == "hello"
+
+
+def test_execute_unknown_tool():
+    result = execute_tool("missing", {}, config={})
+    assert "unknown" in result.lower() or "not found" in result.lower()
+
+
+# ------------------------------------------------------------------
+# output truncation
+# ------------------------------------------------------------------
+
+def test_output_truncation():
+    def big_func(params: dict, config: dict) -> str:
+        return "x" * 100
+
+    tool = ToolDef(
+        name="big",
+        schema={"name": "big", "description": "big", "input_schema": {"type": "object", "properties": {}}},
+        func=big_func,
+        read_only=True,
+        concurrent_safe=True,
+    )
+    register_tool(tool)
+
+    result = execute_tool("big", {}, config={}, max_output=40)
+    # first half = 20 chars, last quarter = 10 chars, marker in between
+    assert len(result) < 100
+    assert "truncated" in result
+    # The kept portion: first 20 + last 10 should be present
+    assert result.startswith("x" * 20)
+    assert result.endswith("x" * 10)
+
+
+def test_no_truncation_when_within_limit():
+    register_tool(_make_echo_tool())
+    result = execute_tool("echo", {"text": "short"}, config={})
+    assert result == "short"
+
+
+# ------------------------------------------------------------------
+# duplicate register overwrites
+# ------------------------------------------------------------------
+
+def test_duplicate_register_overwrites():
+    register_tool(_make_echo_tool("dup"))
+
+    def new_func(params: dict, config: dict) -> str:
+        return "new"
+
+    replacement = ToolDef(
+        name="dup",
+        schema={"name": "dup", "description": "new", "input_schema": {"type": "object", "properties": {}}},
+        func=new_func,
+        read_only=False,
+        concurrent_safe=False,
+    )
+    register_tool(replacement)
+
+    assert len(get_all_tools()) == 1
+    result = execute_tool("dup", {}, config={})
+    assert result == "new"