refactor: hide the concrete agent loop

examples/coding-agent/tests/resume.e2e.ts

@@ -3,7 +3,6 @@ import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { afterEach, describe, expect, it } from 'vitest'
 import type { Context } from 'cordis'
-import type { ReactLoopAgent } from '@deepseek-ai/dsh-agent-loop'
 import { SessionId } from '@deepseek-ai/dsh-session'
 import { codingHarness, finalText, SYSTEM_PROMPT, waitForIdle } from './harness.ts'
 
@@ -41,7 +40,7 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY)('resume: continue a persisted ses
     const first = (await ctx.agents.create({
       sessionId: SESSION_ID,
       agentOptions: { model: 'deepseek-v4-flash' },
-    })).agent as ReactLoopAgent
+    })).agent
     first.send([{ type: 'text', text: `Remember this code for later: ${SECRET}. Just acknowledge it.` }])
     await waitForIdle(ctx, first)
     await ctx.fiber.dispose()
@@ -54,7 +53,7 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY)('resume: continue a persisted ses
     const resumed = (await ctx.agents.resume({
       resumeSessionId: SESSION_ID,
       agentOptions: { model: 'deepseek-v4-flash' },
-    })).agent as ReactLoopAgent
+    })).agent
     expect(resumed.session.id).toBe(SESSION_ID)
     // The prior user turn is in the rehydrated log before the model is asked.
     expect(JSON.stringify(resumed.session.deriveMessages())).toContain(SECRET)