fix(deps): declare dsh-llm as a peer of plan-mode and tool-tasks

Both packages import @deepseek-ai/dsh-llm at runtime (createUserMessage)
but declared it only in devDependencies; any resolver that honors
declared runtime dependencies resolves the import to a stale or missing
artifact. Found by the (since removed) source-launch declared-dependency
check.

packages/plan/plan-mode/package.json

@@ -39,6 +39,7 @@
     "@deepseek-ai/dsh-agent": "^0.0.1",
     "@deepseek-ai/dsh-commands": "^0.0.1",
     "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "@deepseek-ai/dsh-llm": "^0.0.1",
     "@deepseek-ai/dsh-session": "^0.0.1",
     "@deepseek-ai/dsh-session-projection": "^0.0.1",
     "@deepseek-ai/dsh-system-prompt": "^0.0.1",

packages/tasks/tool-tasks/package.json

@@ -32,6 +32,7 @@
   "peerDependencies": {
     "@deepseek-ai/dsh-agent": "^0.0.1",
     "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "@deepseek-ai/dsh-llm": "^0.0.1",
     "@deepseek-ai/dsh-retention": "^0.0.1",
     "@deepseek-ai/dsh-system-prompt": "^0.0.1",
     "@deepseek-ai/dsh-tasks": "^0.0.1",