refactor(tasks): drive wait() timing through dsh-timeout

ctx.tasks.wait arms a deadline() fusing the caller's abort with the
wait timeout and classifies the outcome with timeoutOf scoped to the
new TASK_WAIT_TIMEOUT code: a wait timeout resolves to the live
snapshot (the task keeps running), a caller abort rejects the wait —
same contract, no hand-rolled timer/listener plumbing, and a nested
foreign deadline can no longer misread as a wait timeout. task_output
deliberately declares NO ToolDefinition.timeoutMs: timeout-policy
turns a timed-out call into a structured TOOL_TIMEOUT failure, but a
timed-out wait is a SUCCESS that must still report [status: running]
(decision recorded in the runtime RFC alternatives).

packages/tasks/tasks/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@deepseek-ai/dsh-tasks",
-  "description": "Background task registry (ctx.tasks) for the DeepSeek Harness — shared ids, owner isolation, polling, cancellation, and completion listeners for long-running tool work",
+  "description": "Background task registry (ctx.tasks) for the DeepSeek Harness \u2014 shared ids, owner isolation, polling, cancellation, and completion listeners for long-running tool work",
   "version": "0.0.1",
   "private": true,
   "type": "module",
@@ -24,12 +24,14 @@
   "peerDependencies": {
     "@deepseek-ai/dsh-agent": "^0.0.1",
     "@deepseek-ai/dsh-brand": "^0.0.1",
+    "@deepseek-ai/dsh-timeout": "^0.0.1",
     "cordis": "^4.0.0-rc.6"
   },
   "devDependencies": {
     "@deepseek-ai/dsh-agent": "workspace:^",
     "@deepseek-ai/dsh-brand": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-timeout": "workspace:^",
     "cordis": "^4.0.0-rc.6"
   }
 }