feat(web): make produced-file overflow discoverable

packages/host/apiproxy/tests/api-proxy-workspace.spec.ts

@@ -61,7 +61,10 @@ function stubAgent(session: Session): Agent {
 async function harness(
   root = realpathSync.native(mkdtempSync(join(tmpdir(), 'dsh-apiproxy-workspace-'))),
   picker: DirectoryPickerCapability = { kind: 'native', pick: async () => null },
-  extras: { openPath?: (path: string, signal: AbortSignal) => Promise<void> } = {},
+  extras: {
+    openPath?: (path: string, signal: AbortSignal) => Promise<void>
+    canOpenPath?: () => boolean
+  } = {},
 ) {
   const ctx = new Context()
   await ctx.plugin(SessionStore)
@@ -103,6 +106,7 @@ async function harness(
     defaultModelSelection: () => ({ provider: 'test', model: 'test-model' }),
     cwd: root,
     ...extras.openPath === undefined ? {} : { openPath: extras.openPath },
+    ...extras.canOpenPath === undefined ? {} : { canOpenPath: extras.canOpenPath },
   })
   return { api, ctx, storageDomain, root }
 }
@@ -225,6 +229,13 @@ describe('host.listDirectory / host.createDirectory', () => {
 })
 
 describe('host.openPath', () => {
+  it('describes whether this deployment can reach a user-visible native desktop', async () => {
+    const visible = await harness(undefined, undefined, { canOpenPath: () => true })
+    const headless = await harness(undefined, undefined, { canOpenPath: () => false })
+    expect(expectOk(await visible.api.host.describe(request({}))).canOpenPath).toBe(true)
+    expect(expectOk(await headless.api.host.describe(request({}))).canOpenPath).toBe(false)
+  })
+
   it('opens through the injected native boundary', async () => {
     const opened: string[] = []
     const { api } = await harness(undefined, undefined, {

packages/host/apiproxy/tests/client-handler.spec.ts

@@ -72,7 +72,9 @@ function scriptedApi(overrides: {
       ...overrides.subagents,
     },
     host: {
-      describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0 }),
+      describe: r => ok(r, {
+        version: '0-test', cwd: '/t', attachedSessions: 0, canOpenPath: true,
+      }),
       pickDirectory: r => ok(r, { path: null }),
       listDirectory: r => ok(r, { path: '/t', home: '/t', crumbs: [], entries: [], truncated: false }),
       createDirectory: r => ok(r, { path: '/t/new' }),

packages/host/apiproxy/tests/fetch-carrier.spec.ts

@@ -140,7 +140,13 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
     },
     host: {
       async describe(request) {
-        return { rpcId: request.rpcId, result: { ok: true, value: { version: 'v', cwd: '/w', attachedSessions: 0 } } }
+        return {
+          rpcId: request.rpcId,
+          result: {
+            ok: true,
+            value: { version: 'v', cwd: '/w', attachedSessions: 0, canOpenPath: true },
+          },
+        }
       },
       async pickDirectory(request) {
         return { rpcId: request.rpcId, result: { ok: true, value: { path: null } } }

packages/host/apiproxy/tests/rpc-schemas.spec.ts

@@ -279,10 +279,15 @@ describe('host domain schemas', () => {
   it('validates describe request/value', () => {
     expect(hostDescribeRequestSchema.parse({})).toEqual({})
     const value = hostDescribeValueSchema.parse({
-      version: '1', cwd: '/x', provider: 'p', model: 'm', attachedSessions: 2,
+      version: '1', cwd: '/x', provider: 'p', model: 'm', attachedSessions: 2, canOpenPath: true,
     })
-    expect(value).toMatchObject({ provider: 'p', model: 'm', attachedSessions: 2 })
-    expect(hostDescribeValueSchema.parse({ version: '1', cwd: '/x', attachedSessions: 0 }).provider).toBeUndefined()
+    expect(value).toMatchObject({ provider: 'p', model: 'm', attachedSessions: 2, canOpenPath: true })
+    expect(hostDescribeValueSchema.parse({
+      version: '1', cwd: '/x', attachedSessions: 0, canOpenPath: false,
+    }).provider).toBeUndefined()
+    expect(() => hostDescribeValueSchema.parse({
+      version: '1', cwd: '/x', attachedSessions: 0,
+    })).toThrow()
   })
 
   it('validates the browse listing/creation payloads', () => {