feat(usage): show remaining quota for the current agent account

[Adam-Dalloul]

Remaining usage follows the account saved on the conversation. Switching a Claude chat updates its usage indicator in the same tab, while Token Usage lists accounts and usage windows separately. Agent mentions can select a native account, such as Claude Code · Work, and delegated children retain that account when resumed.

Stacks on #919; merge that first. This refresh includes main 2e657fac and the maintainer's migration-order, locale-order and translated unsupported-agent fixes. It retains the new unified session-settings picker, Claude Remote Control, TRAE CLI and Command Code. This consolidates the earlier panel, header, Cursor and OpenCode Go work from #472, #481, #490 and #491.

Usage reads cover Claude, Codex, Grok, Cursor and OpenCode Go through their official usage interfaces. Named accounts use their own credentials. API/provider overrides do not borrow an old subscription balance. Tighter Claude model limits appear separately, OpenCode Go is labelled explicitly, and missing usage stays unavailable.

The account picker retains a chat's model and mode when switching to an unused account, shows loading/retry states, and offers existing-chat switching on top-level Claude conversations. Remote Control must be turned off before switching, with both a localized UI hint and a backend check that preserves the active connection. Remote Control actions wrap with 44px touch targets on narrow screens. Connecting chats use their own account's cached selectors. These preference and Remote Control fixes are also in #919 so it works independently.

The @ menu derives accounts from the registry and retains native icons and types. delegate_to_agent accepts optional agent_account_id: omission preserves same-agent inheritance, default explicitly chooses Default, and a saved ID chooses that account. Removed or wrong-agent accounts fail before launch. Identical tasks on different accounts remain distinct, and interrupted children resume their saved account. Custom mentions, stored v3 routing frames, and Assistant presets/instructions remain compatible.

Pricing builds on merged #503, included in v0.36.0. The explanation opens by click, tap or keyboard. Partial estimates show how many tokens were priced, unpriced models are labelled, and the explanation states the standard cache-duration assumption and excluded adjustments. These are API list-rate estimates, separate from subscription charges.

Named accounts cover 14 built-in families on Windows/Linux and 13 on macOS. Cursor on macOS uses Default. Kiro, ZCode, TRAE CLI and Command Code retain native agents without named accounts; OpenClaw uses its gateway's account. The account guide and localized backup hint explain that named-account folders need separate backups. OpenCode and Cursor retain the original home/GitHub CLI configuration; other tools using separate configuration folders may need setup.

Validation: 500 focused frontend tests across 19 files, ESLint, TypeScript and production export; the native dependency passes 59 Rust account tests. All 15 focused Rust handshake tests pass after the test-only synchronization fix described below. Runtime fixtures do not perform vendor logins or paid generation.

Separate live checks on Windows verified two distinct existing Claude accounts and authenticated usage reads without changing credentials. No fresh OAuth flow or all-provider sign-in coverage is claimed. OpenCode's installed CLI passed synthetic-store isolation checks while Git, npm and gh retained their configuration; the new OpenCode and Cursor pins were also inspected at source.

The existing office_watch released-port test fix remains: only AddrInUse gets a bounded retry with a fresh candidate; other errors and persistent contention still fail. Windows desktop CI compiles tests and runs Clippy without executing that desktop suite. Browser checks use headless Chromium desktop/phone viewports, not native WebViews or physical phones.

The final server/MCP build and isolated HTTP/MCP/browser checks pass. They cover native and Assistant mentions, explicit Default and inherited accounts, child/Assistant resume, per-account usage, and switching with history/draft/model/mode retained. Pricing shows $22.05 in the full-rate fixture, $21.75 with 75% coverage when a rate is missing, and no invented zero for an unknown model. Desktop 1365px and phone 390px checks cover usage, price help and backup copy. Remote Control checks at 1365px, 390px and 320px verify direct-API refusal while active, unchanged transcript bytes, visible action bounds, QR interaction and the actual Turn off button before switching. Phone contexts use simulated touch.

The first refreshed native Linux run passed 5,413 tests and exposed an existing handshake fixture race: transport shutdown could cancel its close-notification callback. The notification now follows connection completion, retaining the timeout and all assertions. This changes only test synchronization.

Current-head checks for 364a0727.