test(subagent): scope preset round trips to their snapshot scenario

packages/test-support/session-snapshot/tests/fixtures/parent-agent-preset.ts

@@ -1,4 +1,4 @@
-/** Compose a blank headless Session through repeated preset selections. */
+/** Compose a blank headless Session through the scenario's preset selections. */
 
 import type { Context } from '@deepseek-ai/cordis'
 import type {} from '@deepseek-ai/dsh-agent'
@@ -8,13 +8,14 @@ export const name = 'parent-agent-preset'
 export const inject = ['agentPresets']
 
 /**
- * Register the root Session's initial preset selection.
+ * Select the root Session's presets before publication checks.
  * @param ctx - Snapshot composition context with the preset roster.
+ * @param config - Ordered preset selections; omission selects the parent preset once.
  */
-export function apply(ctx: Context): void {
+export function apply(ctx: Context, config: { presets?: string[] } = {}): void {
   ctx.on('agent/created', async ({ agent }) => {
     if (agent.session.header.parentSession !== undefined) return
-    for (const preset of ['parent', 'reviewer', 'parent', 'reviewer', 'parent']) {
+    for (const preset of config.presets ?? ['parent']) {
       await ctx.agentPresets.select(agent, preset)
     }
   }, { prepend: true })

snapshots/session/subagent-agent-preset/cordis.snapshot.yml

@@ -74,6 +74,8 @@
               allowedAgentPresets: [reviewer]
     - id: parent-agent-preset
       name: '../../../packages/test-support/session-snapshot/tests/fixtures/parent-agent-preset.ts'
+      config:
+        presets: [parent, reviewer, parent, reviewer, parent]
 
 - id: tool-subagent
   name: '@deepseek-ai/dsh-tool-subagent'

snapshots/session/subagent-agent-preset/cordis.yml

@@ -33,6 +33,8 @@
               allowedAgentPresets: [reviewer]
     - id: parent-agent-preset
       name: '../../../packages/test-support/session-snapshot/tests/fixtures/parent-agent-preset.ts'
+      config:
+        presets: [parent, reviewer, parent, reviewer, parent]
 
 - id: tool-subagent
   name: '@deepseek-ai/dsh-tool-subagent'