fix(headless): dsh run is a direct core front door

packages/core/agent/tests/model-selection.spec.ts

@@ -3,18 +3,18 @@ import { Context } from 'cordis'
 import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
 import {
   agentEvents,
-  installAgentLlmTarget,
+  installModelSelection,
   type Agent,
-  type AgentLlmTargetRef,
+  type ModelSelectionRef,
 } from '../src/index.ts'
 import { ReasoningEffortId, type LlmCallConfig } from '@deepseek-ai/dsh-llm'
 
-describe('installAgentLlmTarget()', () => {
+describe('installModelSelection()', () => {
   it('snapshots prompt variables and request routing together, then disposes both listeners', async () => {
     const ctx = new Context()
     await ctx.plugin(SystemPrompt)
-    const target: AgentLlmTargetRef = { current: undefined, assembled: undefined }
-    const dispose = installAgentLlmTarget(ctx, target)
+    const selection: ModelSelectionRef = { current: undefined, assembled: undefined }
+    const dispose = installModelSelection(ctx, selection)
     const agent = {} as Agent
     const seed: LlmCallConfig = { provider: 'seed', model: 'seed', temperature: 0.2 }
     const signal = new AbortController().signal
@@ -24,13 +24,13 @@ describe('installAgentLlmTarget()', () => {
       'agent/request', { turn: 1, step: 0, signal }, () => Promise.resolve(seed),
     )).resolves.toBe(seed)
 
-    target.current = {
+    selection.current = {
       provider: 'alpha',
       model: 'a1',
       reasoningEffort: ReasoningEffortId('high'),
     }
     expect((await ctx.systemPrompt.assemble()).variables).toMatchObject({ provider: 'alpha', model: 'a1' })
-    target.current = { provider: 'beta', model: 'b1' }
+    selection.current = { provider: 'beta', model: 'b1' }
     await expect(agentEvents(ctx, agent).waterfall(
       'agent/request', { turn: 1, step: 0, signal }, () => Promise.resolve(seed),
     )).resolves.toEqual({