review: the persona becomes the system-prompt plugin's deployment config

Review round 2 (tianyicui inline comments):

- dsh-system-prompt itself registers the harness:identity (-100) and
  deployment:persona (0) sections — they must survive a swapped loop
  plugin, so they leave dsh-agent-loop; the persona text is the plugin's
  own validated 'persona' config. The model/cwd variables STAY on the
  loop: runtime facts of the agents it drives.
- AgentOptions.systemPrompt is deleted with all its forwarding plumbing:
  the app configs' systemPrompt keys become 'persona' routed through
  dsh-agent-core (schema = z.intersect of the owners'), the ACP bridge
  and tool-subagent stop carrying persona configuration, and subagent
  children now render the deployment persona like every other agent.
- Example personas drop transport/interface trivia (ACP, CLI) — facts
  irrelevant to the model.
- Root CONTEXT.md removed (not idiomatic); its persona definition was
  wrong under the new ownership anyway.
- Docs, READMEs, the prompt-variables RFC, and generated catalogs
  updated; new loop test pins the assemble-waterfall escape valve
  (an emptied assembly sends NO system field).

packages/ui/acp/tests/bridge.spec.ts

@@ -148,15 +148,15 @@ describe('acp bridge', () => {
     await expect(harness.client.authenticate({ methodId: 'whatever' })).resolves.toBeDefined()
   })
 
-  it('honors systemPrompt config', async () => {
+  it('renders the deployment persona into ACP-created agents\' requests', async () => {
     harness = await makeBridgeHarness({
       storageDir,
       script: [textResponse('ok')],
-      config: { systemPrompt: 'be terse' },
+      persona: 'be terse',
     })
     await harness.client.initialize({ protocolVersion: PROTOCOL_VERSION, clientCapabilities: {} })
-    // Create + prompt so the systemPrompt config flows through agentOptions and
-    // reaches the model request.
+    // Create + prompt so the system-prompt plugin's persona section reaches
+    // the model request of an agent the BRIDGE created (session/new).
     const { sessionId } = await harness.client.newSession({ cwd: process.cwd(), mcpServers: [] })
     await harness.client.prompt({ sessionId, prompt: [{ type: 'text', text: 'hi' }] })
     expect(harness.adapter.requests[0]?.system).toContain('be terse')

packages/ui/acp/tests/harness.ts

@@ -153,6 +153,8 @@ export interface BridgeHarness {
 export async function makeBridgeHarness(options: {
   script?: (StreamChunk[] | 'hang')[]
   config?: Partial<AcpConfig>
+  /** Deployment persona for the tree (the system-prompt plugin's config). */
+  persona?: string
   storageDir: string
   /**
    * Plug the REAL `dsh-bash-local` executor + `dsh-tool-bash` tools (instead of
@@ -183,7 +185,7 @@ export async function makeBridgeHarness(options: {
   const ctx = new Context()
   await ctx.plugin(LlmService)
   await ctx.plugin(SessionStore)
-  await ctx.plugin(SystemPrompt)
+  await ctx.plugin(SystemPrompt, { persona: options.persona ?? '' })
   await ctx.plugin(ToolRegistry)
   await ctx.plugin(AgentRegistry)
   await ctx.plugin(AgentLoop, { agents: [] })

packages/ui/acp/tests/stream-update.spec.ts

@@ -818,7 +818,5 @@ describe('agentOptions', () => {
   it('includes only the fields present in config', () => {
     expect(agentOptions({})).toEqual({})
     expect(agentOptions({ model: 'm' })).toEqual({ model: 'm' })
-    expect(agentOptions({ systemPrompt: 'sp' })).toEqual({ systemPrompt: 'sp' })
-    expect(agentOptions({ model: 'm', systemPrompt: 'sp' })).toEqual({ model: 'm', systemPrompt: 'sp' })
   })
 })