Run local usage services in a supervised backend process (#40792)

* Move local usage services into a supervised backend process

* Own usage recovery and worker retirement lifetimes

* Preserve answered usage data during background refresh

* Run independent usage scans concurrently in the backend

* Limit backend startup paths to the delegated usage service

* Show usage failures through backend recovery

* Include usage failure strings in the English catalog

* Keep usage update details beside refresh failures

* Resolve usage freshness failure from the final producer snapshot

* Retain the forced refresh completion requirement

* Keep managed backend failures out of application crash reports

* Preserve usage recovery boundaries across backend reconnects

* Match the backend RPC cancellation signal in the usage seam proof

* Avoid serializing backend requests before port delivery

* Keep receiving request validation in the boundary schemas

* test: align usage transport coverage with renderer project

* fix: preserve unknown usage state and renderer retirement

* fix(usage): revalidate tracking before scan admission

* fix(usage): retry failed backend startup on demand

* test(usage): isolate stale backend ownership checks

src/preload/api/agent-usage-api.ts

@@ -1,3 +1,7 @@
+import type {
+  BackendConnectionListener,
+  BackendConnectionPurpose
+} from '../../shared/backend-service-contract'
 import type { ClaudeUsageBreakdownKind, ClaudeUsageSnapshot } from '../../shared/claude-usage-types'
 import type { CodexUsageBreakdownKind, CodexUsageSnapshot } from '../../shared/codex-usage-types'
 import type {
@@ -25,10 +29,14 @@ export type UsageQueryArgs<Snapshot extends UsageProviderSnapshot> = Pick<
 >
 
 export type UsageProviderApi<Snapshot extends UsageProviderSnapshot, BreakdownKind> = {
-  getScanState: () => Promise<Snapshot['scanState']>
+  onConnectionChanged?: (listener: BackendConnectionListener) => () => void
+  getScanState: (purpose?: BackendConnectionPurpose) => Promise<Snapshot['scanState']>
   setEnabled: (args: { enabled: boolean }) => Promise<Snapshot['scanState']>
   refresh: (args?: { force?: boolean }) => Promise<Snapshot['scanState']>
-  getSnapshot: (args: UsageQueryArgs<Snapshot> & { limit?: number }) => Promise<Snapshot>
+  getSnapshot: (
+    args: UsageQueryArgs<Snapshot> & { limit?: number },
+    purpose?: BackendConnectionPurpose
+  ) => Promise<Snapshot>
   getSummary: (args: UsageQueryArgs<Snapshot>) => Promise<Snapshot['summary']>
   getDaily: (args: UsageQueryArgs<Snapshot>) => Promise<Snapshot['daily']>
   getBreakdown: (

src/preload/api/claude-usage-bridge.ts

@@ -1,8 +1,8 @@
-import { ipcRenderer } from 'electron'
+import { backendUsageTransport } from '../backend-port-client'
 import { createUsageProviderApi } from '../usage-provider-api'
 import type { PreloadApi } from '../api-types'
 
 export const claudeUsageApi = createUsageProviderApi(
-  ipcRenderer,
+  backendUsageTransport,
   'claudeUsage'
 ) satisfies PreloadApi['claudeUsage']

src/preload/api/codex-usage-bridge.ts

@@ -1,8 +1,8 @@
-import { ipcRenderer } from 'electron'
+import { backendUsageTransport } from '../backend-port-client'
 import { createUsageProviderApi } from '../usage-provider-api'
 import type { PreloadApi } from '../api-types'
 
 export const codexUsageApi = createUsageProviderApi(
-  ipcRenderer,
+  backendUsageTransport,
   'codexUsage'
 ) satisfies PreloadApi['codexUsage']

src/preload/api/muse-usage-bridge.ts

@@ -1,8 +1,8 @@
-import { ipcRenderer } from 'electron'
+import { backendUsageTransport } from '../backend-port-client'
 import { createUsageProviderApi } from '../usage-provider-api'
 import type { PreloadApi } from '../api-types'
 
 export const museUsageApi = createUsageProviderApi(
-  ipcRenderer,
+  backendUsageTransport,
   'museUsage'
 ) satisfies PreloadApi['museUsage']

src/preload/api/open-code-usage-bridge.ts

@@ -1,8 +1,8 @@
-import { ipcRenderer } from 'electron'
+import { backendUsageTransport } from '../backend-port-client'
 import { createUsageProviderApi } from '../usage-provider-api'
 import type { PreloadApi } from '../api-types'
 
 export const openCodeUsageApi = createUsageProviderApi(
-  ipcRenderer,
+  backendUsageTransport,
   'openCodeUsage'
 ) satisfies PreloadApi['openCodeUsage']