openai/gpt-5.3-chat → A (15:1)

Commit A introduces a substantial new capability: an extensible external URL foundation with a full GitHub resolver pipeline (API client, rate limiting, DSL generation, system ingest path, UI actions, and browser tests). It also touches many layers (state, write actor, UI, normalization, tests), adding meaningful product functionality. Commit B is a focused improvement to URL display in vote links plus a stronger end-to-end test. While useful, it is comparatively small in scope and impact.