fix(templates): scope template picker to account, not user

The inbox/contact TemplatePicker fetched approved templates filtered by
`user_id = current user`, so in a shared account a teammate only saw
templates they personally created — others' approved templates were
hidden, leaving them unable to send those templates.

message_templates is account-owned and its RLS SELECT policy already
scopes rows to account members (is_account_member, migration 017), so
the user_id filter was both redundant and over-restrictive. Drop it and
rely on RLS, matching the broadcast template picker.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/inbox/template-picker.tsx

@@ -104,10 +104,13 @@ export function TemplatePicker({
         return;
       }
 
+      // Scope by RLS (message_templates_select → is_account_member), NOT by
+      // user_id. Templates are account-owned, so filtering on the caller's
+      // user_id hid templates that a teammate created — leaving them unable
+      // to send approved templates in a shared account.
       const { data, error } = await supabase
         .from("message_templates")
         .select("*")
-        .eq("user_id", user.id)
         .eq("status", "APPROVED")
         .order("created_at", { ascending: false });