docs: add demo GIF from screen recording (README)

ux: print detected issues to stderr before RAG/agents (demo-friendly)

chore: drop pitch doc and trim README to project essentials

fix(api): redirect GET / to /docs to avoid root 404

docs: add ReplayFix API Swagger UI screenshot

feat: With Martian Gateway support (Anthropic SDK base_url + model prefix)

feat: multi-agent orchestration, richer PR evidence, FastAPI detect, pitch doc

chore: pin PyGithub 2.x for Auth.Token support

fix: rename github package to replayfix_github to avoid PyGithub import clash

Initial ReplayFix pipeline and demo app