Discover plugin RPC contracts and move usage displays into Provider Usage

.bb/skills/verify-bb/features/plugin-provider-usage.md

@@ -4,7 +4,7 @@ Status: **2026-09-05: 2 passed, 1 partial/blocked**. See [the audit](../MAINTENA
 
 ## Setup and entry points
 
-Enable Provider usage; configure at least one provider advertising usage maintenance. Open its usage card and Settings → Usage.
+Enable Provider usage and a provider implementing the usage RPC contract. Open its usage card and Settings → Installed plugins → Provider usage.
 
 Use the main skill’s isolated targets and evidence rules. A plugin can be present
 in this checkout but disabled in an installation. Enable it only in the test
@@ -17,14 +17,19 @@ SKILL.md. Inspect nested `--help` before selecting flags and IDs.
 - `plugins/provider-usage/package.json`
 - `plugins/provider-usage/server.ts`
 - `plugins/provider-usage/app.tsx`
+- `plugins/provider-codex/src/usage-source.ts`
+- `plugins/provider-claude-code/src/usage-source.ts`
+- `plugins/provider-acp/src/usage-source.ts`
+- `plugins/account-pool/src/usage-source.ts`
+- `plugins/provider-usage/settings.tsx`
 
 ## Feature recipes
 
 | Feature | Drive | Observable success |
 | --- | --- | --- |
 | All capable providers | Refresh with two supported providers and one unsupported provider. | Cards show only supported data using current provider names/icons and configured ordering. |
 | Quota windows and errors | Inspect real returned windows/resets and a controlled refresh failure. | Values match the provider response; unknown/unavailable data is distinct from exhausted quota. |
-| CLI and SDK parity | Compare bb settings usage --json with bb.sdk.system.usageLimits() and the visible card. | All surfaces represent the same underlying provider maintenance data. |
+| CLI and SDK parity | Inspect `bb plugin rpc list --method provider-usage.v1.listResources --json`, list a provider plugin’s resources, and fetch one returned resource ID. Compare its selected host/provider with `bb settings usage --json`. | Discovery is independent of display plugins, inventory collects no quota, and fetch returns only the chosen resource. Pool resources remain separate from direct host maintenance. |
 
 ## Evidence and cleanup
 
@@ -35,6 +40,15 @@ failed attempts and missing prerequisites as unverified results. Restore plugin
 configuration and remove only this run’s fixtures, registrations, and workers.
 External account changes use authorized disposable targets.
 
-## Maintenance notes
-
-- Open Settings → Usage limits and the sidebar Provider usage disclosure. Compare core settings usage / sdk.system.usageLimits with plugin getUsage, which wraps per-machine providers and normalizes optional fields; it is not byte-for-byte the core response. Source: `plugins/provider-usage/app.tsx:112`.
+## Contract verification
+
+- Test a source with the display plugin disabled. Each provider implementation
+  publishes both source methods independently of the display.
+- Check empty pools, loading, first-load errors, stale measurements after failed
+  refresh, disconnected hosts, and removed resources on both displays.
+- Verify matching window and plan labels, account order, default pool selection,
+  and explicit machine selection. Do not deduplicate by email; known account
+  identities are deduplicated only within the selected location.
+- The settings page fetches resources for the selected location; the footer
+  fetches only its selected provider tab. Compare shared pool sources through
+  their RPC contract; `bb settings usage` remains the direct host-maintenance view.

apps/app/.ladle/config.mjs

@@ -43,6 +43,7 @@ export default {
     "src/**/*.stories.tsx",
     "../../plugins/workflows/**/*.stories.tsx",
     "../../plugins/ask-user-question/*.stories.tsx",
+    "../../plugins/provider-usage/*.stories.tsx",
   ],
   defaultStory: "",
   viteConfig: "./.ladle/vite.config.ts",

apps/app/.ladle/ladle.css

@@ -7,6 +7,7 @@
    the plugin's CSS separately. */
 @source "../../../plugins/automations";
 @source "../../../plugins/provider-retry";
+@source "../../../plugins/provider-usage";
 
 .ladle-main {
   padding: 0;

apps/app/src/App.legacy-skill-route.test.tsx

@@ -77,6 +77,7 @@ describe("legacy resource redirects", () => {
   );
 
   it.each([
+    ["/settings/usage", "/settings/plugins/provider-usage"],
     ["/settings/plugins", "/settings/plugins"],
     ["/extensions?view=installed#catalog", "/plugins?view=installed#catalog"],
     ["/extensions/plugins", "/plugins"],

apps/app/src/App.tsx

@@ -60,6 +60,7 @@ import {
   getAutomationDetailRoutePath,
   getAutomationEditRoutePath,
   getAutomationsRoutePath,
+  getPluginConfigurationRoutePath,
   getSettingsRoutePath,
   getSettingsProjectRoutePath,
 } from "./lib/route-paths";
@@ -264,6 +265,17 @@ export function AppRoutes() {
     <AppLayout>
       <Suspense fallback={null}>
         <Routes>
+          <Route
+            path="/settings/usage"
+            element={
+              <Navigate
+                to={getPluginConfigurationRoutePath({
+                  pluginId: "provider-usage",
+                })}
+                replace
+              />
+            }
+          />
           <Route path={SETTINGS_ROUTE_PATH} element={<SettingsView />} />
           <Route
             path={SETTINGS_SECTION_ROUTE_PATH}

apps/app/src/components/commands/CommandPalette.test.tsx

@@ -263,7 +263,7 @@ describe("CommandPalette", () => {
     expect((searchField() as HTMLInputElement).value).toBe(">");
     const titles = optionTitles();
     expect(titles?.[0]).toContain("New thread");
-    expect(titles).toHaveLength(19);
+    expect(titles).toHaveLength(18);
   });
 
   it("filters as the user types and keeps the selection on a live row", async () => {