feat: use structuredContent with outputSchema in example servers (#220)

* build app-with-deps

* make registerAppTool more interchangeable w/ server.registerTool

* feat: use structuredContent in all example servers

All servers now return structuredContent alongside JSON text content.
All mcp-apps now read structuredContent directly (no JSON.parse fallback).

Updated servers:
- basic-server-vanillajs
- budget-allocator-server
- cohort-heatmap-server
- customer-segmentation-server
- integration-server
- scenario-modeler-server
- system-monitor-server
- threejs-server
- video-resource-server
- wiki-explorer-server

* feat: add outputSchema to all example servers

Define output schemas for structuredContent validation:
- basic-server-vanillajs: { time: string }
- budget-allocator-server: BudgetDataResponseSchema
- cohort-heatmap-server: CohortDataSchema
- customer-segmentation-server: customers/segments schema
- integration-server: { time: string }
- scenario-modeler-server: templates/defaultInputs schema
- system-monitor-server: SystemStatsSchema
- threejs-server: { code, height }
- video-resource-server: { videoUri, description }
- wiki-explorer-server: { page, links, error }

* prettier:fix

* make registerAppTool more interchangeable w/ server.registerTool

* feat: use structuredContent in all example servers

All servers now return structuredContent alongside JSON text content.
All mcp-apps now read structuredContent directly (no JSON.parse fallback).

Updated servers:
- basic-server-vanillajs
- budget-allocator-server
- cohort-heatmap-server
- customer-segmentation-server
- integration-server
- scenario-modeler-server
- system-monitor-server
- threejs-server
- video-resource-server
- wiki-explorer-server

* feat: add outputSchema to all example servers

Define output schemas for structuredContent validation:
- basic-server-vanillajs: { time: string }
- budget-allocator-server: BudgetDataResponseSchema
- cohort-heatmap-server: CohortDataSchema
- customer-segmentation-server: customers/segments schema
- integration-server: { time: string }
- scenario-modeler-server: templates/defaultInputs schema
- system-monitor-server: SystemStatsSchema
- threejs-server: { code, height }
- video-resource-server: { videoUri, description }
- wiki-explorer-server: { page, links, error }

* prettier:fix

* revert: remove unrelated workflow, version, and arch changes

* chore: update package-lock.json

* refactor(basic-server-vanillajs): address PR review comments

- Simplify server.ts to return plain time string in text content (not JSON),
  matching the quickstart guide pattern
- Add defensive coding in mcp-app.ts with optional chaining and fallback
  to handle potential type mismatches gracefully

* refactor: restore rich text formatting for LLM-readable content

Restore the human-readable text formatting functions that were removed,
providing meaningful summaries in the text content while keeping
structuredContent for programmatic UI consumption:

- budget-allocator-server: formatBudgetSummary with config overview
- cohort-heatmap-server: formatCohortSummary with retention stats
- scenario-modeler-server: formatScenarioSummary with financial metrics

examples/customer-segmentation-server/server.ts

@@ -30,6 +30,29 @@ const GetCustomerDataInputSchema = z.object({
     .describe("Filter by segment (default: All)"),
 });
 
+const CustomerSchema = z.object({
+  id: z.string(),
+  name: z.string(),
+  segment: z.string(),
+  annualRevenue: z.number(),
+  employeeCount: z.number(),
+  accountAge: z.number(),
+  engagementScore: z.number(),
+  supportTickets: z.number(),
+  nps: z.number(),
+});
+
+const SegmentSummarySchema = z.object({
+  name: z.string(),
+  count: z.number(),
+  color: z.string(),
+});
+
+const GetCustomerDataOutputSchema = z.object({
+  customers: z.array(CustomerSchema),
+  segments: z.array(SegmentSummarySchema),
+});
+
 // Cache generated data for session consistency
 let cachedCustomers: Customer[] | null = null;
 let cachedSegments: SegmentSummary[] | null = null;
@@ -78,6 +101,7 @@ export function createServer(): McpServer {
         description:
           "Returns customer data with segment information for visualization. Optionally filter by segment.",
         inputSchema: GetCustomerDataInputSchema.shape,
+        outputSchema: GetCustomerDataOutputSchema.shape,
         _meta: { [RESOURCE_URI_META_KEY]: resourceUri },
       },
       async ({ segment }): Promise<CallToolResult> => {
@@ -85,6 +109,7 @@ export function createServer(): McpServer {
 
         return {
           content: [{ type: "text", text: JSON.stringify(data) }],
+          structuredContent: data,
         };
       },
     );