fix(br-1): cloud never falls back to the stream path; final non-http and retry copy

Orca Cloud counts as no screencast until a probe proves otherwise, so a
sleeping or unreachable sandbox cannot surface 'Cannot reach…' stream notices
(BR-2 closes with this). Non-http pages: 'Orca can't show the sandbox's
browser here yet.' + 'This page can only be viewed in the sandbox.' A failed
open says 'Couldn't open the page. Try again.' (polite live region).

src/renderer/src/components/browser-pane/stream-remote/sandbox-only-browser-page-state.fixture.tsx

@@ -1,7 +1,7 @@
 import { defineFixture } from '../../../component-fixtures/component-fixture'
 import { SandboxOnlyBrowserPageState } from './sandbox-only-browser-page-state'
 
-function Pane({ url, error = null }: { url: string; error?: string | null }): React.JSX.Element {
+function Pane({ url, error = false }: { url: string; error?: boolean }): React.JSX.Element {
   return (
     <div className="flex h-[420px] w-[720px] flex-col bg-background text-foreground">
       <div className="border-b border-border px-3 py-2 font-mono text-xs text-muted-foreground">
@@ -29,7 +29,5 @@ export const nonHttp = defineFixture({
 })
 export const openFailed = defineFixture({
   width: 740,
-  render: () => (
-    <Pane url="https://example.org/" error="Could not open the page on this computer." />
-  )
+  render: () => <Pane url="https://example.org/" error />
 })

src/renderer/src/components/browser-pane/stream-remote/sandbox-only-browser-page-state.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest'
 import { canOpenSandboxPageOnThisComputer } from './sandbox-only-browser-page-state'
+import { resolveScreencastSupport } from './use-sandbox-only-browser-page'
 
 describe('canOpenSandboxPageOnThisComputer', () => {
   it('offers http(s) pages, including the sandbox localhost', () => {
@@ -15,3 +16,20 @@ describe('canOpenSandboxPageOnThisComputer', () => {
     expect(canOpenSandboxPageOnThisComputer('not a url')).toBe(false)
   })
 })
+
+describe('resolveScreencastSupport', () => {
+  it('treats a pending or failed probe as no screencast on Orca Cloud', () => {
+    expect(resolveScreencastSupport('pending', true)).toBe(false)
+    expect(resolveScreencastSupport('failed', true)).toBe(false)
+    expect(resolveScreencastSupport(false, true)).toBe(false)
+    // A future orcad that streams is honoured once proven.
+    expect(resolveScreencastSupport(true, true)).toBe(true)
+  })
+
+  it('keeps other hosts on the stream path until the probe says otherwise', () => {
+    expect(resolveScreencastSupport('pending', false)).toBe(null)
+    expect(resolveScreencastSupport('failed', false)).toBe(null)
+    expect(resolveScreencastSupport(true, false)).toBe(true)
+    expect(resolveScreencastSupport(false, false)).toBe(false)
+  })
+})

src/renderer/src/components/browser-pane/stream-remote/sandbox-only-browser-page-state.tsx

@@ -24,11 +24,16 @@ export function SandboxOnlyBrowserPageState({
 }: {
   url: string
   opening: boolean
-  error: string | null
+  /** The last open attempt failed; the button doubles as the retry. */
+  error: boolean
   onOpenOnThisComputer: () => void
 }): React.JSX.Element {
   const t = useTranslate()
   const canOpen = canOpenSandboxPageOnThisComputer(url)
+  const cantShow = t(
+    'auto.components.browser.pane.SandboxOnlyBrowserPage.cantShow',
+    "Orca can't show the sandbox's browser here yet."
+  )
   return (
     <div
       data-testid="sandbox-only-browser-page"
@@ -42,10 +47,12 @@ export function SandboxOnlyBrowserPageState({
         )}
       </div>
       <div className="max-w-sm text-xs leading-5 text-muted-foreground">
-        {t(
-          'auto.components.browser.pane.SandboxOnlyBrowserPage.body',
-          "Orca can't show the sandbox's browser here yet. Open the page on this computer to see it. Pages the agent signed in to will open signed out."
-        )}
+        {canOpen
+          ? t(
+              'auto.components.browser.pane.SandboxOnlyBrowserPage.body',
+              "Orca can't show the sandbox's browser here yet. Open the page on this computer to see it. Pages the agent signed in to will open signed out."
+            )
+          : cantShow}
       </div>
       {canOpen ? (
         <Button size="sm" onClick={onOpenOnThisComputer} disabled={opening}>
@@ -59,11 +66,14 @@ export function SandboxOnlyBrowserPageState({
           )}
         </div>
       )}
-      {error ? (
-        <div role="alert" className="max-w-sm text-xs leading-5 text-destructive">
-          {error}
-        </div>
-      ) : null}
+      <div role="status" aria-live="polite" className="max-w-sm text-xs leading-5 text-destructive">
+        {error && canOpen
+          ? t(
+              'auto.components.browser.pane.SandboxOnlyBrowserPage.openFailed',
+              "Couldn't open the page. Try again."
+            )
+          : null}
+      </div>
     </div>
   )
 }

src/renderer/src/components/browser-pane/stream-remote/use-sandbox-only-browser-page.ts

@@ -4,15 +4,30 @@ import { BROWSER_SCREENCAST_RUNTIME_CAPABILITY } from '../../../../../shared/bro
 import { runtimeEnvironmentSupportsCapability } from '@/runtime/rpc/compatibility/runtime-capability-proof'
 import { openWorkspaceBrowserTab } from '@/lib/browser/workspace/workspace-browser-tab-open'
 import { resolveBrowserSourceUnifiedTab } from '@/lib/browser/workspace/browser-workspace-source-resolution'
+import { isOrcaCloudEnvironmentId } from '@/lib/orca-cloud/orca-cloud-environment-id'
 
 export type SandboxOnlyBrowserPage = {
   /** False when the runtime cannot stream (Orca Cloud's orcad); null while unknown, which keeps the stream path. */
   screencastSupported: boolean | null
   opening: boolean
-  error: string | null
+  error: boolean
   openOnThisComputer: () => void
 }
 
+/**
+ * Whether the stream path may run. Orca Cloud counts as no screencast until a probe proves it (a sleeping or
+ * unreachable sandbox must not fall back to "Cannot reach…" notices); other hosts stay unknown (null) until proven.
+ */
+export function resolveScreencastSupport(
+  probe: 'pending' | 'failed' | boolean,
+  isOrcaCloud: boolean
+): boolean | null {
+  if (typeof probe === 'boolean') {
+    return probe
+  }
+  return isOrcaCloud ? false : null
+}
+
 /**
  * Orca Cloud's orcad hosts agent pages in a headless browser it cannot stream; offer a
  * desktop-hosted copy of the page instead.
@@ -24,25 +39,29 @@ export function useSandboxOnlyBrowserPage(input: {
   worktreeId: string
 }): SandboxOnlyBrowserPage {
   const { pageId, url, runtimeEnvironmentId, worktreeId } = input
-  const [screencastSupported, setScreencastSupported] = useState<boolean | null>(null)
+  const [probe, setProbe] = useState<'pending' | 'failed' | boolean>('pending')
   const [opening, setOpening] = useState(false)
-  const [error, setError] = useState<string | null>(null)
+  const [error, setError] = useState(false)
+  const screencastSupported = resolveScreencastSupport(
+    probe,
+    isOrcaCloudEnvironmentId(runtimeEnvironmentId)
+  )
 
   useEffect(() => {
     let cancelled = false
+    setProbe('pending')
     void runtimeEnvironmentSupportsCapability(
       runtimeEnvironmentId,
       BROWSER_SCREENCAST_RUNTIME_CAPABILITY
     )
       .then((supported) => {
         if (!cancelled) {
-          setScreencastSupported(supported)
+          setProbe(supported)
         }
       })
       .catch(() => {
-        // Unknown support keeps the stream path, which reports its own failures.
         if (!cancelled) {
-          setScreencastSupported(null)
+          setProbe('failed')
         }
       })
     return () => {
@@ -57,7 +76,7 @@ export function useSandboxOnlyBrowserPage(input: {
       worktreeId
     )
     setOpening(true)
-    setError(null)
+    setError(false)
     // A new focused desktop-hosted tab beside this one; the sandbox tab stays so the agent's tab id remains valid.
     // Desktop-hosted cloud pages tunnel loopback through the sandbox, so localhost reaches the sandbox's server.
     void openWorkspaceBrowserTab({
@@ -70,7 +89,7 @@ export function useSandboxOnlyBrowserPage(input: {
       expectedRuntimeEnvironmentId: runtimeEnvironmentId,
       placementPreference: 'auto'
     })
-      .catch((cause) => setError(cause instanceof Error ? cause.message : String(cause)))
+      .catch(() => setError(true))
       .finally(() => setOpening(false))
   }, [pageId, url, runtimeEnvironmentId, worktreeId])
 

src/renderer/src/i18n/locales/en.json

@@ -19011,7 +19011,9 @@
             "title": "Your agent opened this page in the sandbox",
             "body": "Orca can't show the sandbox's browser here yet. Open the page on this computer to see it. Pages the agent signed in to will open signed out.",
             "open": "Open on this computer",
-            "sandboxOnly": "This page can only be viewed in the sandbox."
+            "sandboxOnly": "This page can only be viewed in the sandbox.",
+            "cantShow": "Orca can't show the sandbox's browser here yet.",
+            "openFailed": "Couldn't open the page. Try again."
           }
         },
         "webauthn": {