docs(server): tighten the method-guard comments and changelog

docs/CURRENT-STATE.md

@@ -6491,7 +6491,7 @@ apply to `public/` assets or built-preview serving.
 - `/api/overpass` is bounded by body/response caps, per-client/global rate limits, concurrency limits, operator-configured upstreams, in-flight dedupe, cache bounds, and static validation that every selector is spatially bounded.
 - `/api/military-installations` uses an independent limiter with the same 90-per-client/300-global one-minute bounds, so viewport installation refreshes never consume `/api/overpass` annotation capacity.
 - `/api/route` proxies bounded OSRM route requests for annotation routes, with profile allowlisting, distance caps, response caps, caching, and sanitized "no route found" errors.
-- `/api/flights`, `/api/military`, and `/api/route` are read-only query proxies and answer `405 Method Not Allowed` to anything but `GET`, as `/api/geocode` and the other query proxies already did, declaring `Allow: GET` with it as `/api/radio/stations` does. The refusal precedes rate limiting and any upstream call.
+- `/api/flights`, `/api/military`, and `/api/route` answer `405 Method Not Allowed` with `Allow: GET` to anything but `GET`, before rate limiting and any upstream call.
 - `/api/flights` negotiates gzip. The cached global snapshot and the regional adsb.lol fallback are each gzipped once per refresh (about 860 KB becomes about 250 KB). Clients that offer gzip get that frame; other clients, and bodies under 1 KiB or that gzip cannot shrink, get identity bytes. Both answers carry `Vary: Accept-Encoding`. Uncached bodies, such as auth failures, are never sent under a cached frame's encoding.
 - Track endpoints: `/api/vessels/track?mmsi=` (server-accumulated ring buffers; sub-route handled before the rows snapshot), `/api/flights/track?icao24=` (OAuth, 60s cache, sanitized errors, independent OpenSky credit bucket), `/api/military/track?hex=` (400 for an invalid hex, otherwise `503 history_unavailable` with `Retry-After: 1800` and `Cache-Control: no-store`, no upstream request; military tracking uses its locally accumulated trail).
 - Realtime debug logs redact API keys, bearer tokens, client secrets, and image data URLs before writing to disk; request bodies are size-capped.