📝 docs: simplify README + platform-agnostic tools + auto-create local rules

- Simplify docs/ section to grouped summary with pointer to docs/index.md
- Remove outdated performance metrics table
- Use cross-platform path examples throughout
- Make AGENT_RULES tool usage section platform-agnostic
- Auto-create AGENT_RULES.local.md on sync_rules (empty template)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/playbook.py

@@ -833,6 +833,23 @@ def sync_rules_action(config: dict, context: dict) -> int:
     text = replace_placeholders(text, project_name, date_value, playbook_scripts)
     rules_dst.write_text(text.rstrip("\n") + "\n", encoding="utf-8")
     log("Synced: AGENT_RULES.md")
+
+    local_rules = project_root / "AGENT_RULES.local.md"
+    if not local_rules.exists():
+        local_rules.write_text(
+            "# AGENT_RULES.local\n"
+            "\n"
+            "项目私有规则（优先级高于 AGENT_RULES.md）。\n"
+            "\n"
+            "在此记录：\n"
+            "\n"
+            "- 项目特有的注意事项与常见陷阱\n"
+            "- 同一错误发生 2 次以上时的修正规则\n"
+            "- 团队约定的额外约束\n",
+            encoding="utf-8",
+        )
+        log("Created: AGENT_RULES.local.md")
+
     return 0