test: replace tuple casts with structural lifecycle assertions in command specs

Two aggregate-typecheck errors the package-level tsc -b (rootDir=src) never
saw: the commands spec's two-tuple as-cast over the lifecycle slice
(TS2352, host aggregate) becomes a plain commandId projection, and the
fixture spec still read the deleted result member off the pure-admission
execute value (TS2339, client aggregate) — the matched bit is now asserted
as the whole response shape.

packages/client/connection/tests/fixture-commands.spec.ts

@@ -76,8 +76,8 @@ describe('createFixtureApi commands/skills', () => {
     for (const line of ['/nope', 'plain text', '/']) {
       const response = await api.commands.execute(req({ sessionId: sid('fx-alpha'), line }), signal)
       if (!response.result.ok) throw new Error('execute failed')
-      expect(response.result.value.matched).toBe(false)
-      expect(response.result.value.result).toBeUndefined()
+      // Pure admission value: the matched bit is the whole response shape.
+      expect(response.result.value).toEqual({ matched: false })
     }
   })
 

packages/ui/commands/tests/commands.spec.ts

@@ -307,8 +307,9 @@ describe('CommandService', () => {
       { type: 'command/run', data: { name: 'deploy', line: '/deploy now', source: { kind: 'user' } } },
       { type: 'command/done', data: { kind: 'success', text: 'deployed' } },
     ])
-    const [run, done] = lifecycle as [{ data: { commandId: string } }, { data: { commandId: string } }]
-    expect(run.data.commandId).toBe(done.data.commandId)
+    const ids = lifecycle.map(event => (event.data as { commandId: string }).commandId)
+    expect(ids[0]).toBeTruthy()
+    expect(ids[0]).toBe(ids[1])
     // Zero-step wrap: the pair stays turn-enclosed on an idle log.
     expect(agent.session.events.map(event => event.type)).toEqual([
       'turn/start', 'command/run', 'turn/end',