fix(capa): filter owner dropdown by capa_owner role

Was filtering by non-null department, excluding capa_owner
users who had no department set.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BzvzV91UqHZKM9P58qtvrA

CLAUDE.md

@@ -7,7 +7,7 @@ Replaces WhatsApp/Excel safety reporting. Client: Ms. Agnes, Mr. Terence, Mr. Ya
 ## Stack
 - **Frontend + API routes:** Next.js (App Router)
 - **DB + Auth + Storage:** Supabase (Postgres + RLS + pgvector)
-- **Hosting:** Vercel (frontend) + Supabase cloud
+- **Hosting:** VPS at `http://64.176.82.100/ims/` + Supabase cloud
 - **AI:** Claude API — server-side only, never client-side
 - **Email:** Resend
 - **WhatsApp:** Meta WhatsApp Business Cloud API