fix(#411): QA-005 — production logging, error classification, session-expired state

logAuthError now always logs (not dev-only). Replaced isBackendError with
parseAuthError-based classification. signOut uses proper error type.
Session expiry sets explicit session_expired state. Login page logs in prod.
Fixed pre-existing lint violations in auth package (campsite rule).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/app/(auth)/callback/page.test.tsx

@@ -34,6 +34,8 @@ describe("CallbackPage", (): void => {
       isLoading: false,
       isAuthenticated: false,
       authError: null,
+      sessionExpiring: false,
+      sessionMinutesRemaining: 0,
       signOut: vi.fn(),
     });
   });
@@ -51,6 +53,8 @@ describe("CallbackPage", (): void => {
       isLoading: false,
       isAuthenticated: false,
       authError: null,
+      sessionExpiring: false,
+      sessionMinutesRemaining: 0,
       signOut: vi.fn(),
     });
 
@@ -141,6 +145,8 @@ describe("CallbackPage", (): void => {
       isLoading: false,
       isAuthenticated: false,
       authError: null,
+      sessionExpiring: false,
+      sessionMinutesRemaining: 0,
       signOut: vi.fn(),
     });