Usage fetches only when shown, and can be turned off (#8181)

* fix(usage): fetch only when shown and add a host-wide off switch

* fix(usage): restore policy defaults and isolate usage test state

* refactor(usage): give the sidebar footer sole ownership of its summary

docs/glossary.md

@@ -38,6 +38,7 @@ Authoritative terminology. UI label wins. Don't invent synonyms; use what's here
 - **Usage source** — Plugin registration that discovers accounts and fetches plan usage. Code: `UsageSourceRegistration` (`packages/plugin/src/server/usage.ts`).
 - **Report ID** — Stable daemon-composed identity for one source account: `<sourceId>:<accountKey>`. The source owns the account key; clients treat the whole ID as opaque. Code: `UsageReportEntry.id` (`packages/protocol/src/messages.ts`).
 - **Usage report** — A source's normalized usage for one account, including status and optional windows, balances, and details. Its entry carries the Report ID, account label, and fetch time. Each report renders as one card in the Usage modal, in host Settings, and in an agent's context window details (a hover card on desktop web, a tooltip on native wide screens, a sheet on compact ones), which show only the account that agent runs under, without pins. The hover card and the sheet have Refresh; the native tooltip takes no presses. Code: `UsageReport` (`packages/plugin/src/server/usage.ts`), `UsageCard` (`packages/app/src/usage/card.tsx`), `AgentUsage` (`packages/app/src/usage/agent-usage.tsx`).
+- **Check usage** — Host-wide switch in Usage Settings, on by default. Turning it off stops login discovery and vendor requests on that host for every device. Usage shows an off state with **Turn on**; the sidebar summary and agent usage sections disappear.
 - **Usage (sidebar item)** — The sidebar footer item showing each pinned window's source icon and percent, hidden while no pinned window has data (the footer's Usage icon remains available); both entry points open the Usage modal over the current screen: a dialog on wide layouts, a bottom sheet on compact ones. Usage has no route of its own. Off until the user turns on **Summary in sidebar** (Usage Settings) or the Usage row in Settings > Sidebar; window rows pin only while it is on, and saved pins come back when it is turned on again. A pin is `{ sourceId, windowId }` and shows once per account of that source. Pins and the used/remaining choice are one per-device preference (`AppSettings.usage`) that every usage surface follows. It reads the active workspace's host, else the first connected host with usage sources. Code: `packages/app/src/usage/sidebar-item.tsx`, `usage/usage-modal.tsx`, `usage/pinned.ts`, `usage/preferences.ts`.
 - **Model** — A specific LLM offered by a provider. UI: "Model" / "Select model". Code: `AgentModelDefinition` (`packages/protocol/src/messages.ts:187`).
 - **Tab** — UI surface representing one session inside a workspace. Not a conceptual unit; use **Agent session** when talking about the model. Code: `WorkspaceTabDescriptor` (`packages/app/src/screens/workspace/workspace-tabs-types.ts`).

docs/plugins.md

@@ -550,7 +550,7 @@ string is never inline SVG or a URL.
 
 Register a usage source from `index.server.ts` with `server.registerUsageSource()`. Import `UsageSourceRegistration` and normalization helpers from `@getpaseo/plugin/server/usage`. The plugin owns account discovery, harness labels, and credential-store reads; the daemon owns account grouping and the fetch cache. Agent popovers use only the agent's own login. The host-wide Usage modal falls back across an account's logins; any success shows usage only, and all failures show every login's labeled error and remedy. Follow the [usage source discovery contract](../public-docs/plugins/reference.md#usage-sources). The resolved launch environment crosses into the trusted, unsandboxed plugin subprocess for session discovery. Usage queries never run lifecycle hooks. Inputs are validated in the plugin process and remain daemon-side. `icon` uses the same SVG file rules as provider icons.
 
-The daemon calls discovery for `usage.list_reports`; the client gates this RPC on `server_info.features.usageSources`. The old `provider.usage.list` RPC maps discovered reports for older clients.
+When the host’s **Check usage** switch is off, the daemon rejects usage requests before discovery, without reading logins or calling vendors. Otherwise, the daemon calls discovery for `usage.list_reports`; the client gates this RPC on `server_info.features.usageSources`. The old `provider.usage.list` RPC maps discovered reports for older clients.
 
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