fix(design): connect video preparation and playable history

tests/unit/works-square-design-workspace.test.ts

@@ -94,7 +94,30 @@ describe('Works Square V2 Design Workspace adapter', () => {
     const fetchMock = vi.fn(async (input: string | URL) => {
       const url = String(input);
       if (url.endsWith('/api/design/capabilities')) {
-        return jsonResponse({ conversation: true, generation: true, image: true, video: true });
+        return jsonResponse({
+          conversation: true,
+          generation: true,
+          image: true,
+          video: true,
+          generation_options: {
+            image: {
+              available: true,
+              supported_aspect_ratios: ['1:1', '3:4', '9:16', '4:3', '16:9'],
+              supported_duration_seconds: [],
+              max_output_count: 4,
+              requires_first_frame: false,
+              supported_reference_roles: ['inspiration'],
+            },
+            video: {
+              available: true,
+              supported_aspect_ratios: ['1:1', '3:4', '9:16', '4:3', '16:9'],
+              supported_duration_seconds: [1, 6, 12],
+              max_output_count: 1,
+              requires_first_frame: true,
+              supported_reference_roles: ['first_frame'],
+            },
+          },
+        });
       }
       if (url.includes('/api/design/workspaces?')) return jsonResponse([serverSummary]);
       if (url.endsWith('/api/design/workspaces/workspace-1')) return jsonResponse(serverWorkspace);
@@ -168,6 +191,33 @@ describe('Works Square V2 Design Workspace adapter', () => {
         },
       },
     },
+    {
+      command: {
+        kind: 'apply_input' as const,
+        workspaceId: 'workspace-1',
+        sessionId: 'session-1',
+        expectedDirectionRevision: 4,
+        clientOperationId: 'operation-prepare-1',
+        input: {
+          kind: 'prepare_generation' as const,
+          operations: [
+            { kind: 'set' as const, path: 'intent.media', value: 'video' },
+          ],
+        },
+      },
+      expected: {
+        client_command_id: 'operation-prepare-1',
+        name: 'design.input.apply',
+        input: {
+          expected_direction_revision: 4,
+          client_operation_id: 'operation-prepare-1',
+          input: {
+            kind: 'prepare_generation',
+            operations: [{ kind: 'set', path: 'intent.media', value: 'video' }],
+          },
+        },
+      },
+    },
     {
       command: {
         kind: 'confirm_generation' as const,