fix: close 0.1.66 release blockers

[Minorli]

Summary

• close the confirmed image error, PNG-8 mask, deep error payload, font subset, event-loop, authorization, and configured reasoning gaps from the 0.1.66 checklist
• scale official-logo detection from the request canvas to resampled result canvases and persist preservation diagnostics
• make favorites, result-count notices, itinerary confirmation/title rendering, and team-chat polling/room transitions match the actual product behavior
• scope the Arco shell refresh to simple mode while keeping professional-mode pixels unchanged outside the required mode button and "我的收藏" copy exceptions
• bump package, image, documentation, and static cache versions to 0.1.66

Additional review fixes

• convert Pillow decompression-bomb failures for unsupported preflight formats such as TIFF into the existing controlled mask-composite fallback
• hide the "我的收藏" summary whenever the favorite-only filter is cleared
• prevent an older chat read completion from clearing an error produced by a newer message request

Verification

• ./scripts/check.sh: 442 passed; Ruff clean; Mypy clean
• uv run --with coverage coverage run --source=src/picgen -m pytest -q: 439 passed before the three review regressions were added; source coverage 88%. The final 442-test snapshot passed through ./scripts/check.sh.
• node --check static/app.js, static/logo-placement.mjs, and static/responses-settings.mjs: passed
• uvx pip-audit: no known vulnerabilities
• Playwright: simple shell at 1440/1040/900/821/375 px, result-count warning, itinerary confirmation, unchanged chat polling, and cross-room send isolation passed with no console errors
• professional pixel diff: zero changed pixels after masking the required mode-button and C1 copy regions
• real A3 generate/edit: gpt-5.6-sol + xhigh, requested/final 1088x2240; edited upstream image 874x1799 normalized to 1088x2240
• PIL logo check: generated score 0.9534, edited score 0.9507, original scores 0, exactly one high-confidence official logo in each final image

Notes

• The source checklist expected an uncommitted 0.1.65 worktree, but 0.1.65 had already shipped through PR fix: highlight the interface mode toggle #38 and that worktree/branch no longer existed. The shipped mode-button change is retained and covered as part of C6.
• No runtime dependency was added and no API contract was expanded beyond the authorized cross-user favorite visibility behavior.