refactor(client): name the compile face in every client test filename

A test file under packages/client now says which face it covers:
`*.client.spec.{ts,tsx}` and its `*.client.{ts,tsx}` helpers belong to the
Client aggregate, `*.host.spec.ts` to the host aggregate. The carrier's four
node-half specs take the Host suffix.

The two suffixes are mutually exclusive, so each aggregate excludes the
other's and both keep one broad test glob: `exclude` wins over `include`, and
`packages/client/**` no longer has to be excluded wholesale from the host
program with per-file `files` entries carved back out of it. A Host-face spec
that reaches only Host source therefore needs no cross-face project
reference, which the split-project rule rejects.

vitest still discovers every file through `**/*.spec.{ts,tsx}`.

packages/client/ui-conversation/tests/host.client.spec.ts

@@ -0,0 +1,30 @@
+import { Context } from '@deepseek-ai/cordis'
+import { describe, expect, it } from 'vitest'
+import { Settings, settingsNamespace, type SettingsNamespace } from '@deepseek-ai/dsh-settings'
+import {
+  CONVERSATION_SETTINGS_NAMESPACE, DEFAULT_BUSY_ENTER_BEHAVIOR, apply,
+} from '@deepseek-ai/dsh-client-ui-conversation'
+
+class MemorySettings extends Settings {
+  readonly writable = true
+  protected load(): Promise<Record<string, unknown>> { return Promise.resolve({}) }
+  protected persist(_ns: SettingsNamespace, _section: Record<string, unknown>): Promise<void> {
+    return Promise.resolve()
+  }
+}
+
+describe('ui-conversation host', () => {
+  it('registers, validates, and disposes the durable busy-Enter preference', async () => {
+    const ctx = new Context()
+    await ctx.plugin(MemorySettings).await()
+    const fiber = ctx.plugin({ apply })
+    await fiber.await()
+    const ns = settingsNamespace(CONVERSATION_SETTINGS_NAMESPACE)
+    expect(ctx.settings.get(ns)).toEqual({ busyEnter: DEFAULT_BUSY_ENTER_BEHAVIOR })
+    await ctx.settings.update(ns, { busyEnter: 'steer' })
+    expect(ctx.settings.get(ns)).toEqual({ busyEnter: 'steer' })
+    await expect(ctx.settings.update(ns, { busyEnter: 'invalid' })).rejects.toThrow()
+    await fiber.dispose()
+    expect(ctx.settings.describe().map(row => row.ns)).not.toContain(ns)
+  })
+})