fix(10-04): prettier format + remove unnecessary type assertions

- Run prettier on all new/modified PWA files (CredentialSheet, SetupBanner, AdminPage, admin.spec.ts)
- Remove unnecessary 'as React.RefObject<HTMLElement | null>' casts flagged by @typescript-eslint/no-unnecessary-type-assertion
- Format pre-existing API files from Plans 02/03 (me.ts, user.test.ts, requireAdmin.test.ts, me.test.ts)
- All 270 API tests + 191 PWA vitest tests pass; lint/typecheck/build clean

apps/api/tests/auth/user.test.ts

@@ -314,7 +314,15 @@ describe('upsertUser', () => {
       }
       // Re-fetch after insert
       return makeSelectChain([
-        { id: 10, oidcIss: iss, oidcSub: sub, displayName: null, color: COLOR_PALETTE[0], isAdmin: true, createdAt: new Date() },
+        {
+          id: 10,
+          oidcIss: iss,
+          oidcSub: sub,
+          displayName: null,
+          color: COLOR_PALETTE[0],
+          isAdmin: true,
+          createdAt: new Date(),
+        },
       ]);
     });
     mockDb.insert.mockReturnValue(makeInsertChain([{ id: 10 }]));
@@ -344,7 +352,15 @@ describe('upsertUser', () => {
         return makeSelectChain([{ count: 1 }]);
       }
       return makeSelectChain([
-        { id: 11, oidcIss: iss, oidcSub: sub, displayName: null, color: COLOR_PALETTE[1], isAdmin: false, createdAt: new Date() },
+        {
+          id: 11,
+          oidcIss: iss,
+          oidcSub: sub,
+          displayName: null,
+          color: COLOR_PALETTE[1],
+          isAdmin: false,
+          createdAt: new Date(),
+        },
       ]);
     });
     mockDb.insert.mockReturnValue(makeInsertChain([{ id: 11 }]));