~anthropic/claude-sonnet-latest → B (6:4)

Side B consolidates three parallel legacy POST endpoints (/post, /post/check, /post/redact) into the single /ui RPC dispatch path, removing duplicated auth/session logic (web_post.rs deleted entirely) and updating tests/fixtures accordingly—this is a substantive architectural simplification with real behavioral consolidation. Side A mainly swaps a cookie-based theme system for a /~/ URL-based browse route and deletes CSS themes, which is a reasonable but narrower and more cosmetic refactor (URL scheme change plus theme removal) with less overall reduction in duplicated logic.