feat: add async sampling and elicitation tools

Add tools that demonstrate bidirectional MCP tasks where the server
sends requests to the client for async execution:

- trigger-sampling-request-async: Send sampling request with task
  params, client creates task and executes LLM call in background,
  server polls for completion and retrieves result

- trigger-elicitation-request-async: Same pattern for user input,
  useful when user may take time to fill out forms

Both tools:
- Check client capabilities (tasks.requests.sampling/elicitation)
- Accept both CreateTaskResult and direct result responses
- Poll tasks/get for status updates
- Fetch final result via tasks/result

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/everything/tools/index.ts

@@ -14,6 +14,8 @@ import { registerToggleSubscriberUpdatesTool } from "./toggle-subscriber-updates
 import { registerTriggerElicitationRequestTool } from "./trigger-elicitation-request.js";
 import { registerTriggerLongRunningOperationTool } from "./trigger-long-running-operation.js";
 import { registerTriggerSamplingRequestTool } from "./trigger-sampling-request.js";
+import { registerTriggerSamplingRequestAsyncTool } from "./trigger-sampling-request-async.js";
+import { registerTriggerElicitationRequestAsyncTool } from "./trigger-elicitation-request-async.js";
 import { registerSimulateResearchQueryTool } from "./simulate-research-query.js";
 
 /**
@@ -45,4 +47,7 @@ export const registerConditionalTools = (server: McpServer) => {
   registerTriggerSamplingRequestTool(server);
   // Task-based research tool (uses experimental tasks API)
   registerSimulateResearchQueryTool(server);
+  // Bidirectional task tools - server sends requests that client executes as tasks
+  registerTriggerSamplingRequestAsyncTool(server);
+  registerTriggerElicitationRequestAsyncTool(server);
 };