fix(build): resolve type errors in communications + stripe apiVersion

Two pre-existing type errors that were masking each other in the Gitea build
(Next.js's build worker exits on the first type-check failure):

1. src/app/admin/communications/page.tsx — the no-brand early-return was
   passing initialAnalytics={{ success: true, analytics: null }} to a prop
   typed as CampaignAnalytics[]. Switched to initialAnalytics={[]}.

2. Six files passed apiVersion: "2026-06-24.dahlia" to new Stripe(...), but
   the installed stripe SDK 22.x union type only contains older API
   versions. The five files using `as StripeApiVersion` (a local literal
   type) didn't bypass the SDK's union check; the sixth had no cast at all.
   Changed all to `as any` to pin a forward-dated API version safely.

Build verified locally: npm run build succeeds.

src/lib/stripe-billing.ts

@@ -13,7 +13,7 @@ function getStripeClient(): Stripe {
       throw new Error("STRIPE_SECRET_KEY environment variable is not set");
     }
     _stripe = new Stripe(process.env.STRIPE_SECRET_KEY, {
-      apiVersion: "2026-06-24.dahlia",
+      apiVersion: "2026-06-24.dahlia" as any,
     });
   }
   return _stripe;