Perf: optimize WVO logo assets

[Artsen]

Summary

• Replaces the two large WVO logo PNGs with transparent lossless WebP assets.
• Updates app logo constants, README logo references, and brand-system docs to use WebP.
• Refreshes curated README screenshots from deterministic review captures.

Size Impact

• WVO-logo-transparent.png: 2,008,932 bytes removed.
• WVO-logo-white-transparent.png: 2,115,578 bytes removed.
• WVO-logo-transparent.webp: 26,718 bytes added.
• WVO-logo-white-transparent.webp: 43,058 bytes added.

The app logo pair drops from 4,124,510 bytes to 69,776 bytes, about a 98.3% reduction.

Asset Notes

• Optimized assets are 768x512 WebP with alpha (argb).
• They were generated from the approved PNG artwork using lossless WebP encoding and a practical source width for UI/README use.
• The PNG favicon remains unchanged.
• No app workflow, API, dependency, Docker, or media-processing behavior changed.

Verification

• npm run format:check: passed.
• npm run test:run --workspace apps/web -- AppMark: passed, 1 test.
• npm run review:ui-screens: passed, 1 screenshot review test.
• npm run check: passed, 388 tests passed, 1 skipped.
• git diff --check: passed.

Visual Review

• Checked optimized dark-letter logo on a light app-like background.
• Checked optimized white-letter logo on a dark app-like background.
• Regenerated deterministic UI screenshots and refreshed the six curated README WebP screenshots.