feat(playwright): adopt per-thread sessions for shared Chrome automation

skills/xiaohongshu-engage/SKILL.md

@@ -15,10 +15,18 @@ description: "Browse XiaoHongShu (小红书) with Playwright and execute account
 
 ## Shared Session Policy
 
-- Reuse a single Playwright CLI session across all web-automation skills:
-  - `export PLAYWRIGHT_SHARED_SESSION=codex-shared`
+- Use per-thread Playwright CLI sessions across all web-automation skills:
+  - Auto session policy: `tools/pw` derives one Playwright session per `CODEX_THREAD_ID` (fallback: `PLAYWRIGHT_SESSION_OWNER` or explicit `--session`).
 - Use `/Users/xd/java/xhs/tools/pw` as the only Playwright CLI entrypoint.
-- Do not pass `--session` directly in skill-specific commands.
+- Prefer the default auto session; pass `--session <name>` only when explicit isolation is required.
+
+## Network Preflight Gate (Required)
+
+- Before first browser step, run:
+  - `tools/pw --help`
+- If it fails with network sandbox signatures (`ENOTFOUND`, `EAI_AGAIN`, `ETIMEDOUT`, `ECONNREFUSED`, or `registry.npmjs.org` fetch failure):
+  - rerun the same command with escalation (`sandbox_permissions=require_escalated`).
+- Do not continue browsing/点赞/收藏/评论 until this preflight succeeds.
 
 ## 1) Confirm Login State