feat: rename activities; keep original Garmin title as a tag

Add Activity.original_name (migrated via init_db ALTER). The rename
endpoint stores the import title the first time a user renames and
clears it if renamed back. Activity detail page gets inline rename
(pencil) UI and shows the original title beneath the new name; the
activities list shows it as a small tag too.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CLAUDE.md

@@ -115,13 +115,16 @@ docker compose -f docker-compose.deploy.yml up -d
 - `App.jsx` — React Router v6, `RequireAuth` wrapper, all routes defined here
 - `hooks/useAuth.js` — Zustand store for auth state, reads JWT from `localStorage`, handles PocketID token-in-URL flow
 - `hooks/useSync.js` — Zustand store polling Garmin sync status; maps backend status strings to progress percentages
+- `hooks/useUnits.js` — Zustand store for the global km/mi display preference (`useUnit()` subscribes to the active unit). Distances are stored canonically; the unit only affects display, converted on the fly by the `format.js` helpers. Persisted to `localStorage`. Surfaced in the nav via `components/ui/UnitToggle.jsx`
+- `hooks/useMediaQuery.js` — responsive breakpoint hook (md=768px split); the dashboard widget grid must be conditionally mounted, not just CSS-hidden, on mobile
 - `utils/api.js` — Axios instance with JWT interceptor and 401→redirect handler
-- TanStack Query (`@tanstack/react-query`) handles all server-state fetching and caching; Zustand is used only for auth state
+- TanStack Query (`@tanstack/react-query`) handles all server-state fetching and caching; Zustand is used only for auth, sync, and unit-preference state
 - `utils/format.js` — shared formatting helpers: `formatDuration`, `formatPace`, `formatDistance`, `formatCadence`, `hrZoneColor`, `sportIcon`, `sportColor`, etc.
 - `utils/track.js` — projects a lat/lng onto a GPS track (interpolated along-line snapping, used for map hover and segment selection); `utils/bodyBattery.js` — shared Body Battery colour/state helpers used by both the Health page and Dashboard mini chart
 - `pages/` — one `*Page.jsx` file per route: `Dashboard` (drag-to-edit widget grid), `Activities`, `ActivityDetail`, `Routes`, `Records`, `Health`, `Upload`, `Profile`, `Users`, `Login`
 - `components/activity/` — `ActivityMap` (Leaflet), `MetricTimeline` (Recharts), `HRZoneBar`, `LapTable`, `SegmentsPanel` (per-activity segment efforts), `RouteLeaderboard` (top-10 by pace for a named route)
-- `components/ui/` — `Layout` (nav shell), `StatCard`, `RouteMiniMap` (small Leaflet map used in route/segment cards)
+- `components/health/` — `SleepHypnogram` (renders the `sleep_stages` hypnogram)
+- `components/ui/` — `Layout` (nav shell), `StatCard`, `RouteMiniMap` (small Leaflet map used in route/segment cards), `UnitToggle` (km/mi switch), `HrvBadge`
 
 The Vite dev server proxies `/api` to `http://backend:8000` (for use inside the Docker Compose network). The production build bakes `VITE_API_URL` at build time.
 
@@ -147,6 +150,8 @@ curl -s https://gitea.jarrett.eu/api/v1/repos/owain/MileVault/actions/tasks
 ```
 The runner builds images on-host, so local image digests won't match the registry — verify a deploy landed by `docker exec`-ing into the running container and grepping the changed source, not by comparing digests.
 
+Always deploy the changes requested, do not prompt the user whether to deploy.
+
 ## Environment variables
 
 Required in `.env` (or passed to Docker Compose):