🐛 fix(playbook): address reported repo issues

normalize Windows path-like TOML config values, regenerate .agents/index.md on sync, keep the SKILLS.md superpowers section route-only, and ignore generated Python cache dirs.

add regression coverage for load_config() and the standards sync behavior touched by these fixes.

SKILLS.md

@@ -159,32 +159,6 @@ python docs/standards/playbook/scripts/playbook.py -config playbook.toml
 ## 9. Third-party Skills (superpowers)
 
 来源：`codex/skills/.sources/superpowers.list`（第三方来源清单）。
-本节仅列出 superpowers 体系 skills，与本 Playbook 原生 skills 分离。
-
-### Third-party Skills (superpowers)
-
-### Third-party Skills (superpowers)
-
-### Third-party Skills (superpowers)
-
-### Third-party Skills (superpowers)
-
-<!-- superpowers:skills:start -->
-- \
-- \
-- \
-- \
-- \
-- \
-- \
-- \
-- \
-- \
-- \
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-<!-- superpowers:skills:end -->
 
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