`match_suffix` emits non-HTTP methods (`WEBSOCKET`) into `http_methods`

[rahlk]

Is your feature request related to a problem? Please describe.

_methods_of in codeanalyzer/entrypoints/matching.py returns the matched suffix unconditionally:

if source == "match_suffix":
    verb = (qualified or dec.qualified_name or "").rsplit(".", 1)[-1]
    return [verb.upper()]

_HTTP_VERBS exists in the same module (line 29) and is applied on the other method path (line 207), but not here. The shipped heuristic.http-verb rule matches {*,*.*}.{get,post,put,patch,delete,head,options,websocket}, so @app.websocket("/ws") produces http_methods: ["WEBSOCKET"].

WEBSOCKET is not an HTTP method. http_methods is a field consumers filter on to separate routes from non-route entrypoints, so a junk value there is worse than an empty list — a query for "all POST endpoints" is unaffected, but a query that enumerates distinct methods now reports a method that does not exist.

The framework rules using match_suffix (flask.bp-verb, fastapi.verb, fastapi.router-verb) list only real verbs and are unaffected today; the heuristic tier is the live case, and any future rule with a non-verb suffix inherits the same gap.

Describe the solution you'd like

• _methods_of's match_suffix branch returns [verb.upper()] only when verb.lower() in _HTTP_VERBS, else [].
• Test: a @app.websocket("/ws") fixture registers an entrypoint with http_methods == [], and a @app.get fixture still yields ["GET"].

Describe alternatives you've considered

Not stated in the original issue.

Additional context

Scope boundary

• The fix is one filter, matching what line 207 already does. No rule change and no schema change: http_methods shrinks in the affected case, gains nothing new.
• fastapi.websocket (a separate rule with no methods: spec) already yields [] and is not the case here.

Caveats and known risks

• This is a behaviour change for anyone reading WEBSOCKET out of http_methods today. The entrypoint record is still produced — only the method list changes — and rule (heuristic.http-verb) remains the way to identify the shape.

Definition of done

http_methods contains only members of _HTTP_VERBS for every entrypoint the shipped ruleset produces, asserted by a test over a websocket-decorated fixture; existing entrypoint tests unchanged.

Cross-language note

Found while adding JS/TS framework rules in codeanalyzer-typescript#206, which fixed the same bug class on its own export_name path (Astro's ALL export). TypeScript's match_suffix branch already filtered; this one does not.