Release v0.2.34

Standards conformance + Apache/nginx parity:
- Conformance suites: IANA status (exhaustive), RFC 6265 cookies, RFC 9110 IMF-date,
  HTTP/1.1 framing & request smuggling (RFC 9112 §6-§7), live traversal proof.
- CI gates: 80% coverage floor (codecov), Infection mutation testing (minMsi 55 /
  covered 60), perf-regression smoke. STANDARDS.md catalogue.
- Middleware: ScopedMiddleware, RequestHeaderMiddleware, MergeSlashesMiddleware,
  BodySizeLimitMiddleware, RefererMiddleware, ReturnMiddleware.
- Fixes: #23 session pipe-format cross-server parity, #25 .php URLs 404 not 403.