Format catch block in oauth-pkce.ts to satisfy Biome lint

The single-line ``catch { /* ... */ }`` form introduced by the OAuth
PKCE middleware commit failed ``biome check`` in CI. Expand to
multi-line so ``make lint`` passes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: rustyconover

src/http/oauth-pkce.ts

@@ -864,7 +864,9 @@ export function handleEarlyReturnTo(request: Request, config: OAuthPkceConfig):
         return null;
       }
     }
-  } catch { /* not a JWT or can't decode — proceed with redirect */ }
+  } catch {
+    /* not a JWT or can't decode — proceed with redirect */
+  }
 
   // Already authenticated with a return_to — redirect back with the token
   const separator = returnTo.includes("#") ? "&" : "#";