Add a deterministic (method, path) read/write classifier with an explicit
render-only override table that can only downgrade provably side-effect-free
POSTs (markdown/markup) to reads, never the reverse — so a mutating call cannot
slip past the write-mode gate. Add a known-Gitea-prefix gate: gitea_request now
fails closed on any path whose top segment is not a recognized /api/v1 route
instead of passing unknown paths through. Expose raw_relative_segments for the
authorization layer.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
