feat(bilibili): add creator analytics adapter

[ele-yufo]

What changed

• add opencli bilibili creator-stats <owned-bvid> for creator-only manuscript diagnostics, conversion, and retention data
• use the supported browser page.fetchJson() primitive with the current creator-center login session
• preserve complete metric paths while reporting every value as platform_raw instead of inferring percentages, seconds, or scores
• classify invalid arguments, missing videos, expired login/permissions, ownership mismatch, transport failures, malformed schemas, and valid empty analytics with typed errors
• add focused adapter tests, generated manifest metadata, and Bilibili command documentation

Strategy note

• Strategy: PAGE_FETCH at the data-contract level, represented by registry Strategy.COOKIE to acquire the logged-in browser session.
• Contract: internal-unstable.
• Observed sources: public /x/web-interface/view plus authenticated creator-center /archive_diagnose/compare, /archive_diagnose/play_analyze, and /archive/analyze/graph endpoints.
• Public API is insufficient because it lacks creator-only completion, audience, conversion, peer-baseline, and retention fields.
• UI/DOM extraction is not safer because the creator center renders selected summaries and chart state rather than the complete raw metric paths.
• Maintenance boundary: these endpoints are undocumented and may drift. The adapter fails closed on envelope/schema changes and deliberately avoids semantic unit conversion.

Validation

• real logged-in E2E against one owned manuscript: 255 rows across four source groups
• creator play count matched both the public video endpoint and the visible creator-center manuscript card; creator duration matched the visible card duration
• opencli browser ... verify bilibili/creator-stats --strict-memory: fixture match
• invalid BVID: ARGUMENT, exit 2
• valid non-owned BVID: AUTH_REQUIRED, exit 77
• focused Vitest: 9/9 passed
• full test suite: 587 files, 6593 tests passed, 1 skipped
• npm run build, npm run typecheck, npm run docs:build
• npm run check:typed-error-lint, npm run check:silent-column-drop
• opencli validate bilibili/creator-stats

Known limitations

• deep analytics require an active creator-center login and an owned manuscript
• the retention graph currently uses the first cid; multipart manuscript per-part selection is not exposed yet
• internal creator-center endpoint or field drift will require maintenance; raw paths make that drift explicit rather than silently mislabeling values