refactor: update tests, McpServer, and examples for TaskManager API

- Update protocol.test.ts to construct TaskManager and pass to Protocol
- Remove assertTaskCapability/assertTaskHandlerCapability from test subclasses
- Update McpServer to use extra.task?.taskStore instead of extra.taskStore
- Update example server to use extra.task.taskStore/taskId/requestedTtl
- Update core task interfaces for TaskContext grouping

All packages now typecheck cleanly with zero errors.

Author: felixweinberger

examples/server/src/simpleStreamableHttp.ts

@@ -484,16 +484,16 @@ const getServer = () => {
             }
         },
         {
-            async createTask({ duration }, { taskStore, taskRequestedTtl }) {
+            async createTask({ duration }, extra) {
                 // Create the task
-                const task = await taskStore.createTask({
-                    ttl: taskRequestedTtl
+                const task = await extra.task.taskStore.createTask({
+                    ttl: extra.task.requestedTtl
                 });
 
                 // Simulate out-of-band work
                 (async () => {
                     await new Promise(resolve => setTimeout(resolve, duration));
-                    await taskStore.storeTaskResult(task.taskId, 'completed', {
+                    await extra.task.taskStore.storeTaskResult(task.taskId, 'completed', {
                         content: [
                             {
                                 type: 'text',
@@ -508,11 +508,11 @@ const getServer = () => {
                     task
                 };
             },
-            async getTask(_args, { taskId, taskStore }) {
-                return await taskStore.getTask(taskId);
+            async getTask(_args, extra) {
+                return await extra.task.taskStore.getTask(extra.task.taskId);
             },
-            async getTaskResult(_args, { taskId, taskStore }) {
-                const result = await taskStore.getTaskResult(taskId);
+            async getTaskResult(_args, extra) {
+                const result = await extra.task.taskStore.getTaskResult(extra.task.taskId);
                 return result as CallToolResult;
             }
         }