docs(api): drop stale ACUC reference from unverified-cap comment (firecrawl#3991)

The comment cited ACUC.adjusted_credits_used as the old credit source; that
field is being removed (ACUC no longer authoritative for credits). Keep the
"Autumn is the source of truth" explanation without the vestigial reference.

Co-authored-by: firecrawl-spring[bot] <254786068+firecrawl-spring[bot]@users.noreply.github.com>
Co-authored-by: micahstairs <micah@sideguide.dev>

Author: firecrawl-spring[bot]

apps/api/src/routes/shared.ts

@@ -77,10 +77,10 @@ export function checkCreditsMiddleware(
           }
 
           // Enforce 50-credit cap for unverified agent keys. Autumn is the
-          // source of truth for credit usage now (not ACUC.adjusted_credits_used):
-          // getTeamBalance().usage is the team's credits used this period. If
-          // Autumn is unavailable we fail open (skip the cap), matching the
-          // Autumn-outage behavior of the main credit check below.
+          // source of truth for credit usage: getTeamBalance().usage is the
+          // team's credits used this period. If Autumn is unavailable we fail
+          // open (skip the cap), matching the Autumn-outage behavior of the
+          // main credit check below.
           const UNVERIFIED_CREDIT_LIMIT = 50;
           let unverifiedCreditsUsed: number | null = null;
           try {