feat: Add Hall of Fame leaderboard backed by a dedicated results table

feat: Replace llama.cpp backend with in-process transformers backend for local GPU inference

feat(roadmap): add comprehensive arena roadmap outlining sessions, winners, and leaderboard features

docs: add as-built Fishbowl UI architecture page

feat: add Fishbowl UI presenter layer and say-vs-think engine support

feat: add Fishbowl UI ADR and implementation plan for Gradio presenter layer

feat: update model endpoint URLs and enhance documentation with mermaid diagrams

feat: add architecture review and scenario authoring documentation

feat: update setup instructions and dependencies for uv integration

Refactor code structure for improved readability and maintainability

feat: phase 2 architecture — manifest system, structured output, salience memory, SQLite ledger, observer