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/skill/tools.py

@@ -0,0 +1,110 @@
+"""Skill tool: lets the model invoke skills by name via tool call."""
+from __future__ import annotations
+
+from tool_registry import ToolDef, register_tool
+from .loader import find_skill, load_skills, substitute_arguments
+
+
+_SKILL_SCHEMA = {
+    "name": "Skill",
+    "description": (
+        "Invoke a named skill (reusable prompt template). "
+        "Use SkillList to see available skills and their triggers."
+    ),
+    "input_schema": {
+        "type": "object",
+        "properties": {
+            "name": {
+                "type": "string",
+                "description": "Skill name (e.g. 'commit', 'review')",
+            },
+            "args": {
+                "type": "string",
+                "description": "Arguments to pass to the skill (replaces $ARGUMENTS)",
+                "default": "",
+            },
+        },
+        "required": ["name"],
+    },
+}
+
+_SKILL_LIST_SCHEMA = {
+    "name": "SkillList",
+    "description": "List all available skills with their names, triggers, and descriptions.",
+    "input_schema": {
+        "type": "object",
+        "properties": {},
+        "required": [],
+    },
+}
+
+
+def _skill_tool(params: dict, config: dict) -> str:
+    """Execute a skill by name and return its output."""
+    skill_name = params.get("name", "").strip()
+    args = params.get("args", "")
+
+    # Look up by name first, then by trigger
+    skill = None
+    for s in load_skills():
+        if s.name == skill_name:
+            skill = s
+            break
+    if skill is None:
+        skill = find_skill(skill_name)
+    if skill is None:
+        names = [s.name for s in load_skills()]
+        return f"Error: skill '{skill_name}' not found. Available: {', '.join(names)}"
+
+    rendered = substitute_arguments(skill.prompt, args, skill.arguments)
+    message = f"[Skill: {skill.name}]\n\n{rendered}"
+
+    # Run inline via agent and collect text output
+    import agent as _agent
+    system_prompt = config.get("_system_prompt", "")
+
+    # Collect output text
+    output_parts: list[str] = []
+    sub_state = _agent.AgentState()
+    sub_config = {**config, "_depth": config.get("_depth", 0) + 1}
+    try:
+        for event in _agent.run(message, sub_state, sub_config, system_prompt):
+            if hasattr(event, "text"):
+                output_parts.append(event.text)
+    except Exception as e:
+        return f"Skill execution error: {e}"
+
+    return "".join(output_parts) or "(skill completed with no text output)"
+
+
+def _skill_list_tool(params: dict, config: dict) -> str:
+    skills = load_skills()
+    if not skills:
+        return "No skills available."
+    lines = ["Available skills:\n"]
+    for s in skills:
+        triggers = ", ".join(s.triggers)
+        hint = f"  args: {s.argument_hint}" if s.argument_hint else ""
+        when = f"\n    when: {s.when_to_use}" if s.when_to_use else ""
+        lines.append(f"- **{s.name}** [{triggers}]{hint}\n  {s.description}{when}")
+    return "\n".join(lines)
+
+
+def _register() -> None:
+    register_tool(ToolDef(
+        name="Skill",
+        schema=_SKILL_SCHEMA,
+        func=_skill_tool,
+        read_only=False,
+        concurrent_safe=False,
+    ))
+    register_tool(ToolDef(
+        name="SkillList",
+        schema=_SKILL_LIST_SCHEMA,
+        func=_skill_list_tool,
+        read_only=True,
+        concurrent_safe=True,
+    ))
+
+
+_register()