feat(xiaohongshu): add 4 creator analytics commands (creator-profile, creator-stats, creator-notes, creator-note-detail) (#49)

* feat(xiaohongshu): add 4 creator analytics commands

Add creator backend support for Xiaohongshu (小红书), enabling
creators to access their analytics data from the command line.

New commands:
- creator-profile: account info (followers, likes, creator level)
- creator-stats: 7-day/30-day overview (views, likes, collects,
  comments, shares, new followers) with daily trend data
- creator-notes: note list with per-note metrics from note manager
- creator-note-detail: single note analytics breakdown
  (organic vs promoted vs video traffic)

API discovery:
- /api/galaxy/creator/home/personal_info (cookie auth, 200 OK)
- /api/galaxy/creator/data/note_detail_new (cookie auth, 200 OK)
- /api/galaxy/creator/data/note_detail?note_id=xxx (cookie auth, 200 OK)
- Note manager DOM extraction for note list (bypasses v2 signature)

All endpoints verified working with real creator account.
Screenshots (redacted) included in docs/screenshots/.

Requires: Chrome logged into creator.xiaohongshu.com

* chore: remove screenshots from repo (will host externally for PR)

* review: fix creator analytics CLI integration

Co-authored-by: stone16 <stone2paul@gmail.com>

* test: add site-scoped test runner

Co-authored-by: stone16 <stone2paul@gmail.com>

* review: ignore publish timestamps in creator note metrics

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Co-authored-by: jackwener <jakevingoo@gmail.com>