Add a secret:NAME arm to GalaxySecretRef.ResolveApiKey that resolves the Galaxy
gateway API key through the shared ISecretResolver — fail-closed if the secret is
absent (never falls through to the cleartext literal arm), retiring the dev:/literal
in-DB path for production. Because GetAsync is async the method becomes
ResolveApiKeyAsync; the await cascade threads ISecretResolver by ctor injection into
GalaxyDriver + GalaxyDriverBrowser and (since GalaxyDriver is built by a static
factory closure, not DI) through GalaxyDriverFactoryExtensions + DriverFactoryBootstrap
(which pulls the real resolver from the service provider — registered unconditionally
in Slice 1). A NullSecretResolver null-object backs the parse-only/test paths only;
the runtime path always gets the real resolver (verified end-to-end).
TDD: 3 new secret:-arm tests (resolve / fail-closed-on-absent / no-literal-warning)
RED without the arm, GREEN with it; 338 Galaxy tests pass; no sync-over-async.
Adds <summary>/<param>/<returns>/<inheritdoc> where missing and removes
project bookkeeping IDs (task/tracking refs) from shipped code comments,
so the docs read cleanly and CommentChecker is quiet except for known
false positives (PLC/protocol terms, event/IEqualityComparer inheritdoc).
Doc/comment-only; no logic changed; solution builds clean.
Joseph Doherty