feat(skill/playwright): unify shared-session CLI flow for web skills

skills/gemini-music-web/SKILL.md

@@ -20,13 +20,17 @@ description: "Generate music in Gemini web via browser automation, download resu
 
 - Ensure browser session can access Gemini (`https://gemini.google.com/app`).
 - If login, captcha, or MFA is required, pause and ask user to complete it manually.
+- Use the shared Playwright session policy across all skills:
+  - `export PLAYWRIGHT_SHARED_SESSION=codex-shared`
+  - Invoke Playwright CLI through `/Users/xd/java/xhs/tools/pw` (do not pass `--session` manually).
 - Decide output directory before generation, for example:
   - `/Users/xd/java/xhs/output/gemini-music`
 
 Quick run:
 
 ```bash
-bash scripts/run_music_flow.sh \
+export PLAYWRIGHT_SHARED_SESSION=codex-shared
+python3 scripts/run_music_flow.py \
   --prompt "创作一段 90 BPM 的 lo-fi hiphop，温暖、夜晚、钢琴和刷镲，时长 30 秒。" \
   --target /Users/xd/java/xhs/output/gemini-music \
   --count 1
@@ -152,5 +156,6 @@ Return:
 
 ## Scripts
 
-- `scripts/run_music_flow.sh`: End-to-end runner (login gate, enter music tool, generate, download MP3, collect files).
+- `/Users/xd/java/xhs/tools/pw`: Shared Playwright CLI entrypoint with fixed session + lock.
+- `scripts/run_music_flow.py`: End-to-end runner (login gate, enter music tool, generate, download MP3, collect files).
 - `scripts/collect_downloads.py`: Collect recent downloaded audio files with fallback sources, dedupe, and manifest.