Adds scripts/har_capture_cdp.py for browsers reached over CDP -- cloud
backends (Browserbase, Browser-Use, Firecrawl), Camofox-with-CDP, and any
/browser connect endpoint. record_har_path only works on a locally-owned
Playwright context, so the CDP capturer attaches via connect_over_cdp() and
assembles the HAR from page request/response events instead, leaving the
attached browser open (it doesn't own it).
- SKILL.md: pathway->capturer routing table, CDP prerequisites, pitfalls for
wrong-capturer/empty-HAR, headless-UA weakness, and no-close-on-attach
- Validated live: attached to an external CDP Chrome, drove DuckDuckGo
autocomplete, derived the /ac/ endpoint, replayed it browserless
- tests: assert CDP capturer attaches (not launches) and that the skill
documents every browser backend
