fix(assistant): surface shape bugs — films scope mime hint, apps_list items wrap

Two reasons the content surface 'often doesn't surface the content':

- content.indeehub-projects items carried no mime/filename, so the UI
  adapter classified every film 'excluded' and the films grid could never
  render. They are films: they now declare video/mp4.
- apps_list surfaced the container-list RPC's BARE ARRAY; the broker reads
  { items: [...] }, so the apps grid was silently dropped every turn.
  Wrapped at the tool boundary — the shared RPC's own shape is untouched.

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

core/archipelago/src/api/rpc/content.rs

@@ -1223,6 +1223,11 @@ impl RpcHandler {
                     "synopsis": p.synopsis.clone().unwrap_or_default(),
                     "poster": p.poster.clone().unwrap_or_default(),
                     "year": p.year_num(),
+                    // Films are video by definition. The UI adapter buckets
+                    // purely on mime/extension, so an item carrying neither
+                    // silently classified 'excluded' and this scope's
+                    // surface could never render a card.
+                    "mime_type": "video/mp4",
                 }))
             })
             .collect();