fix: add error handling to meetings + verband dashboard pages

SSR pages crash with 500 when Supabase queries fail (expired session,
network issues). Now catch errors and render with empty data instead
of crashing the entire page.

Dockerfile

@@ -5,7 +5,7 @@ WORKDIR /app
 # --- Install + Build in one stage ---
 FROM base AS builder
 # CACHE_BUST: change this value to force a full rebuild (busts Docker layer cache)
-ARG CACHE_BUST=12
+ARG CACHE_BUST=13
 RUN echo "Cache bust: ${CACHE_BUST}"
 COPY . .
 RUN pnpm install --no-frozen-lockfile