fix: harden getActiveContext and add error logging on presentations page

- getActiveContext now verifies team still exists (teams.get) before
  trusting the cookie/prefs tenantId, preventing stale E Ofis cookie
  from causing an onboarding redirect loop
- Resolved tenantId from getUserTeams() is now persisted to cookie so
  subsequent requests skip the resolution path
- Added catch+log on presentations data fetch to surface the actual
  error in server logs

src/app/(dashboard)/presentations/page.tsx

@@ -25,7 +25,10 @@ export default async function PresentationsPage() {
         Query.limit(200),
       ],
     }),
-  ]);
+  ]).catch((e) => {
+    console.error("[PresentationsPage] data fetch failed:", e);
+    throw e;
+  });
 
   const presentations = JSON.parse(JSON.stringify(presResult.rows)) as Presentation[];