UI store, API coverage, and rate-limit retries

Status: Accepted
Date: 2025-12-24
Context:
- Shared UI state (theme, toasts, label/health caches) needed to live in the AppStore to match the yewdux architecture rule.
- The API client needed coverage for health, metrics, and label list endpoints to unblock upcoming screens.
- Rate-limit responses required user-visible backoff messaging and a safe retry path for idempotent fetches.
Decision:
- Move shell theme/toast/busy state into the AppStore and populate label/health caches from API calls.
- Extend the UI API client with health/full, metrics, and label list endpoints, leaving option/selection/authoring calls for later UI wiring.
- Handle 429 responses for torrent list/detail fetches with Retry-After backoff and a single retry.
Consequences:
- UI state is centralized and ready for labels/health screens without ad-hoc local state.
- API coverage is aligned with the checklist endpoints, reducing future wiring churn.
- Rate-limit retries add controlled delay behavior; repeated throttling still surfaces errors.
Follow-up:
- Remove demo-only list/detail fallback paths and add empty states.
- Implement category/tag management screens and health viewer UI.
- Wire per-torrent options/selection editing in the drawer and add torrent authoring UX.

Motivation

Keep shared UI state in yewdux and close API coverage gaps needed for Torrent UX.

AppShell theme and toast lifecycles now flow through AppStore updates.
Labels/health caches are populated from API calls and stored in dedicated slices.
Added API client methods for remaining torrent and label endpoints.
API client currently covers health/full, metrics, and label list endpoints; mutating endpoints await UI wiring.
Rate-limit backoff uses Retry-After with a single retry for idempotent list/detail fetches.

just ci (fmt, lint, check-assets, udeps, audit, deny, ui-build, test, test-features-min, cov)
llvm-cov reports: “warning: 40 functions have mismatched data”