Answer the structured-session support probe without installing the host (#18695)

* Answer the structured-session support probe without installing the host

`getStructuredAgentSessionCreateSupport` called `ensureStructuredAgentSessionHost()`
before answering, so a read-only "can you create a Codex session here?" question
performed the create route's lifecycle work: the first install opens the durable
agent-session record store, attaches the PTY write-gate record lookup and starts
the orphan-child reaper.

Ask the pure predicate instead. `supportsCreate` on the installed host resolves to
`adapterSupportsCreate`, which for the Codex adapter is exactly
`agent === 'codex' && supportsCodexStructuredLocation(location)` — no adapter
instance is needed to answer it.

Nothing is lost: the create/attach route still installs via `ensureStructuredHostInstalled`,
and startup restoration still installs and reconciles when a store is already persisted.

* test(runtime): cover structured support probe parity

---------

Co-authored-by: Merge Sim <sim@local>

src/main/runtime/orca-runtime-resolve-recovered-structured-tui-transcript.ts

@@ -3,6 +3,8 @@ import { OrcaRuntimeWithStopStructuredSessionProcess } from './orca-runtime-stop
 import type { AgentSessionOwnerBinding } from '../../shared/agent-session-host-authority'
 import { agentSessionOwnerBindingsEqual } from '../../shared/claimed-agent-pty-owner-snapshot'
 import { resolvePinnedCodexRolloutProof } from '../codex/codex-tui-rollout-proof'
+import { supportsCodexStructuredLocation } from '../codex/codex-structured-location-support'
+import { supportsClaudeStructuredLocation } from '../claude/claude-structured-location-support'
 import { getStructuredAgentSessionHost } from '../native-chat/agent-session-wire/structured-agent-session-registry'
 import { resolveStructuredAgentSessionCreateSupport } from '../native-chat/structured-agent-session-create-support'
 import { LOCAL_EXECUTION_HOST_ID } from '../../shared/execution-host'
@@ -51,13 +53,13 @@ export class OrcaRuntimeWithResolveRecoveredStructuredTuiTranscript extends Orca
     agent: 'claude' | 'codex'
   ): Promise<{ supported: boolean; reason?: 'agent' | 'remote' | 'wsl' }> {
     const location = await this.resolveStructuredAgentSessionLocation(worktreeSelector)
-    await this.ensureStructuredAgentSessionHost()
-    // The verdict lives in a typechecked module; this file is @ts-nocheck.
     return resolveStructuredAgentSessionCreateSupport({
       agent,
       location,
       adapterSupportsCreate:
-        getStructuredAgentSessionHost()?.supportsCreate(location, agent) === true,
+        agent === 'claude'
+          ? supportsClaudeStructuredLocation(location)
+          : supportsCodexStructuredLocation(location),
       getSettings: () => this.requireStore().getSettings()
     })
   }

src/main/runtime/structured-agent-session-support-probe.test.ts

@@ -0,0 +1,174 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { OrcaRuntimeService } from './orca-runtime'
+import {
+  getStructuredAgentSessionHost,
+  setStructuredAgentSessionHost
+} from '../native-chat/agent-session-wire/structured-agent-session-registry'
+import { agentSessionPtyWriteGate } from './agent-session-pty-write-gate'
+
+type InstallEffects = {
+  storeOpened: boolean
+  writeGateAttached: boolean
+  reaperStarted: boolean
+}
+
+/** Stands in for `install()` by performing the three effects it performs, so a probe that
+ *  reinstalls the host is caught by what the install *does*, not by a call count alone. */
+function stubStructuredHostInstall(runtime: OrcaRuntimeService): {
+  effects: InstallEffects
+  ensure: ReturnType<typeof vi.fn>
+} {
+  const effects: InstallEffects = {
+    storeOpened: false,
+    writeGateAttached: false,
+    reaperStarted: false
+  }
+  // `supportsCreate` answers as the real Codex adapter would, so a probe that reinstalls the host
+  // still returns the right answer and fails on the install effects alone.
+  const host = {
+    reconcileRestartLeases: vi.fn(async () => {}),
+    supportsCreate: (location: { executionHostId: string; wslDistro: string | null }) =>
+      location.executionHostId === 'local' && location.wslDistro === null
+  }
+  const ensure = vi.fn(async () => {
+    effects.storeOpened = true
+    effects.reaperStarted = true
+    agentSessionPtyWriteGate.attachRecordLookup(() => null)
+    effects.writeGateAttached = true
+    setStructuredAgentSessionHost(host as never)
+  })
+  vi.spyOn(runtime, 'ensureStructuredAgentSessionHost').mockImplementation(ensure)
+  return { effects, ensure }
+}
+
+type TestLocation = {
+  executionHostId: string
+  wslDistro: string | null
+  workspaceKind?: 'folder' | 'git-worktree'
+}
+
+type SupportResult = {
+  supported: boolean
+  reason?: 'agent' | 'remote' | 'wsl'
+}
+
+function createRuntime(location: TestLocation): OrcaRuntimeService {
+  const runtime = new OrcaRuntimeService({ getSettings: () => ({}) } as never)
+  const internal = runtime as unknown as {
+    resolveStructuredAgentSessionLocation: () => Promise<unknown>
+  }
+  internal.resolveStructuredAgentSessionLocation = vi.fn(async () => ({
+    executionHostId: location.executionHostId,
+    wslDistro: location.wslDistro,
+    workspaceId: 'workspace-1',
+    workspaceKind: location.workspaceKind ?? 'git-worktree'
+  }))
+  return runtime
+}
+
+async function expectSupportWithoutInstall(input: {
+  agent: 'claude' | 'codex'
+  location: TestLocation
+  expected: SupportResult
+  repetitions?: number
+}): Promise<void> {
+  const runtime = createRuntime(input.location)
+  const { effects, ensure } = stubStructuredHostInstall(runtime)
+
+  const answers: SupportResult[] = []
+  for (let index = 0; index < (input.repetitions ?? 1); index += 1) {
+    answers.push(
+      await runtime.getStructuredAgentSessionCreateSupport('id:workspace-1', input.agent)
+    )
+  }
+
+  expect(answers).toEqual(Array(input.repetitions ?? 1).fill(input.expected))
+  expect(ensure).not.toHaveBeenCalled()
+  expect(effects).toEqual({
+    storeOpened: false,
+    writeGateAttached: false,
+    reaperStarted: false
+  })
+  expect(getStructuredAgentSessionHost()).toBeNull()
+}
+
+describe('structured agent-session create-support probe', () => {
+  afterEach(() => {
+    setStructuredAgentSessionHost(null)
+    agentSessionPtyWriteGate.detachRecordLookup()
+    vi.restoreAllMocks()
+  })
+
+  it.each(['codex', 'claude'] as const)(
+    'answers %s support repeatedly without installing the host',
+    async (agent) => {
+      await expectSupportWithoutInstall({
+        agent,
+        location: { executionHostId: 'local', wslDistro: null },
+        expected: { supported: true },
+        repetitions: 3
+      })
+    }
+  )
+
+  it.each(['codex', 'claude'] as const)(
+    'still reports an unsupported remote %s location without installing the host',
+    async (agent) => {
+      await expectSupportWithoutInstall({
+        agent,
+        location: { executionHostId: 'ssh-host-1', wslDistro: null },
+        expected: { supported: false, reason: 'remote' }
+      })
+    }
+  )
+
+  it.each(['codex', 'claude'] as const)(
+    'still reports an unsupported WSL %s location without installing the host',
+    async (agent) => {
+      await expectSupportWithoutInstall({
+        agent,
+        location: { executionHostId: 'local', wslDistro: 'Ubuntu' },
+        expected: { supported: false, reason: 'wsl' }
+      })
+    }
+  )
+
+  it.each(['codex', 'claude'] as const)(
+    'supports a local folder workspace for %s without installing the host',
+    async (agent) => {
+      await expectSupportWithoutInstall({
+        agent,
+        location: {
+          executionHostId: 'local',
+          wslDistro: null,
+          workspaceKind: 'folder'
+        },
+        expected: { supported: true }
+      })
+    }
+  )
+
+  it('still installs and reconciles on startup when a store is already persisted', async () => {
+    const runtime = createRuntime({ executionHostId: 'local', wslDistro: null })
+    const { effects, ensure } = stubStructuredHostInstall(runtime)
+    const internal = runtime as unknown as {
+      hasPersistedStructuredAgentSessionStore: () => boolean
+      refreshMobileSessionPtyRecords: () => Promise<void>
+    }
+    internal.hasPersistedStructuredAgentSessionStore = () => true
+    internal.refreshMobileSessionPtyRecords = vi.fn(async () => {})
+
+    await runtime.prepareStructuredAgentSessionStartupRestoration()
+
+    expect(ensure).toHaveBeenCalledTimes(1)
+    expect(effects).toEqual({
+      storeOpened: true,
+      writeGateAttached: true,
+      reaperStarted: true
+    })
+    expect(
+      (getStructuredAgentSessionHost() as unknown as { reconcileRestartLeases: () => void })
+        .reconcileRestartLeases
+    ).toHaveBeenCalledTimes(1)
+  })
+})