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/executor.py

@@ -0,0 +1,66 @@
+"""Skill execution: inline (current conversation) or forked (sub-agent)."""
+from __future__ import annotations
+
+from typing import Generator
+
+from .loader import SkillDef, substitute_arguments
+
+
+def execute_skill(
+    skill: SkillDef,
+    args: str,
+    state,
+    config: dict,
+    system_prompt: str,
+) -> Generator:
+    """Execute a skill.
+
+    If skill.context == "fork", runs as an isolated sub-agent and yields its events.
+    Otherwise (inline), injects the rendered prompt into the current agent loop.
+
+    Args:
+        skill: SkillDef to execute
+        args: raw argument string from user (after the trigger word)
+        state: AgentState
+        config: config dict (may contain _depth, model, etc.)
+        system_prompt: current system prompt string
+    Yields:
+        agent events (TextChunk, ToolStart, ToolEnd, TurnDone, …)
+    """
+    rendered = substitute_arguments(skill.prompt, args, skill.arguments)
+    message = f"[Skill: {skill.name}]\n\n{rendered}"
+
+    if skill.context == "fork":
+        yield from _execute_forked(skill, message, config, system_prompt)
+    else:
+        yield from _execute_inline(message, state, config, system_prompt)
+
+
+def _execute_inline(message: str, state, config: dict, system_prompt: str) -> Generator:
+    """Run skill prompt inline in the current conversation."""
+    import agent as _agent
+    yield from _agent.run(message, state, config, system_prompt)
+
+
+def _execute_forked(
+    skill: SkillDef,
+    message: str,
+    config: dict,
+    system_prompt: str,
+) -> Generator:
+    """Run skill as an isolated sub-agent (separate conversation context)."""
+    import agent as _agent
+
+    # Build a sub-agent config with depth tracking
+    depth = config.get("_depth", 0) + 1
+    sub_config = {**config, "_depth": depth, "_system_prompt": system_prompt}
+    if skill.model:
+        sub_config["model"] = skill.model
+
+    # Restrict tools if skill specifies allowed-tools
+    if skill.tools:
+        sub_config["_allowed_tools"] = skill.tools
+
+    # Run in fresh state (no shared history)
+    sub_state = _agent.AgentState()
+    yield from _agent.run(message, sub_state, sub_config, system_prompt)