docs: add developer guides for architecture, testing, and code review

fix: skip encoding_format for Ollama embeddings

fix: complete test audit — all 52 issues resolved, ruff clean

changing the default bridge url to Anthropic's official API endpoint

fix: entry point plugins loaded but never executed, plus test suite audit

docs: mark HTTP interface parity as done in ROADMAP

docs: update ROADMAP to reflect current state

docs: clarify premium features require sr2-pro

Initial commit: SR2 v1.0.0 — context engineering library for AI agents