Backlog, tests, logo compression, security audit, App Store icon

- BACKLOG.md: P0-P3 roadmap incl. govuk API switch (blocked on credentials)
- APPSTORE.md: review-gate analysis (2 blockers: LAN data source, Always-location notes)
- SECURITY.md: audit - no secrets, no ATS holes, one MEDIUM (relay IP in binary, planned fix)
- FuelBoardTests/: SPM package, 28 tests on real Shared/ sources (sanitizer, price guard, RAG, sort, distance, brands)
- Logos: proper 2x/3x pairs, palette-quantized, 75% smaller (315KB -> 79KB)
- App icon: 1024px fuelpump on gradient (was missing entirely -> instant rejection)
- decodeStations(from:) exposed for testability; relay fetch reuses it

BACKLOG.md

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+# FuelBoard Backlog
+
+FuelBoard — England-wide petrol-station price widget + app.
+Relay mirrors the UK gov data (hourly CSV); app fetches the full-UK dump
+(~8,038 stations, all prices) once per 12 h and filters/sorts on-device.
+
+Priority guide: P0 = next build, P1 = soon, P2 = later, P3 = maybe/idea.
+Status: TODO / IN PROGRESS / DONE / BLOCKED.
+
+---
+
+## P0 — Next build
+
+- [ ] **Switch dataset to govuk API data** (BLOCKED on credentials)
+  Register at developer.fuel-finder.service.gov.uk (GOV.UK One Login / OAuth 2.0).
+  Relay already supports an OAuth provider upgrade path — `client_id`/`client_secret`
+  go into relay `.env`, never into the IPA. Live API replaces the hourly CSV mirror;
+  endpoint/schema mapping (E5/E10/DIESEL → FuelType) already proven in
+  `FuelPriceProvider.swift`. Until credentials arrive, the CSV mirror stays.
+  Any credentials received must be treated as secrets ([REDACTED] storage).
+
+## P1 — Soon
+
+- [ ] **Unit test target for the app** — XCTest target covering:
+  - `FuelStore.sanitizedStationTitle` (title-case chunks, Sainsbury's apostrophe,
+    acronyms BP/MFG/ASDA/MOTO, hyphen/paren chunks, mixed-case passthrough)
+  - decode price guard: grades outside 50–500 pence/litre dropped
+    (`FuelPriceProvider.allPrices` + legacy `price` fallback)
+  - RAG thresholds (≤1.5p green / ≤4p amber / >4p red)
+  - Cheapest-vs-Closest sort + delta/TOP baseline (cheapest-within-radius both modes)
+  - miles→km and km→miles conversions (× 1.60934 / × 0.621371)
+- [ ] **Backlog hygiene** — mark implemented items DONE, prune obsolete entries
+- [ ] **EV charging?** — National Chargepoint Registry as a 4th "Charging" tab
+  (second relay endpoint, ~40k+ UK chargers, OGL, connector-type filter) vs fuel-only.
+
+## P2 — Later
+
+- [ ] **Widget configuration** — let the widget's fuel be chosen per-widget
+  (App Intent `FuelSelectionIntent` + `StaticConfiguration` → `AppIntentConfiguration`),
+  instead of inheriting the app's selected fuel. Requires iOS 17 `AppIntentConfiguration`.
+- [ ] **CarPlay** — widgets render but can't launch Maps; consider a proper CarPlay
+  scene (CPListTemplate) for navigation deep-links.
+- [ ] **Alert region tuning** — make alert trigger radius + dedup window
+  user-configurable (currently fixed 300 m trigger / 1 per station per hour).
+- [ ] **Pull-to-refresh spinner state** — surface refresh in-flight state
+  (currently `refreshable` fires but no visible progress in the row list).
+- [ ] **Offline first-run** — first launch without network currently shows empty
+  states; bundle a sample dump so the app demos offline.
+- [ ] **Localization** — UK English only today; audit string catalog for l10n.
+- [ ] **Dark mode polish** — verify brand logos (white-circle clips) and RAG dot
+  contrast under dark appearance on-device.
+
+## P3 — Ideas / Research
+
+- [ ] **Fuel-price prediction** — trend from historical dumps (relay could keep a
+  rolling archive) to show "price tends up/down".
+- [ ] **Price alerts for a specific station** — notify when a starred station's
+  price drops below a user threshold.
+- [ ] **Share sheet** — share "Cheapest Unleaded near me" as text/image card.
+- [ ] **Watch app** — glanceable cheapest-price complication (WatchKit + shared
+  app-group store; watch target would need to be added to the project).
+- [ ] **App Clip** — 10 MB budget for "find cheapest fuel nearby" without install.
+
+## Done (recent)
+
+- [x] England-wide full-UK dump, on-device filtering (relay `142061b`, app `cf9765b`)
+- [x] Cache-first, 12 h gate, pull-to-refresh only
+- [x] Distance filter 5/10/15 miles, local-only changes (no re-fetch)
+- [x] Closest mode = whole country, distance picker disabled
+- [x] Delta/TOP baseline = cheapest-within-radius in both modes
+- [x] Three-layer price sanitisation (relay band 50–500p / app decode guard / title-case)
+- [x] Title-case station names (chunk-aware sanitizer)
+- [x] Native large-title navigation (Mail-style collapse) — `313fe84`
+- [x] E10/E5 bracket labels in picker + descriptions — `05f3ef0`
+- [x] Gitea remotes created + pushed (`apt/fuelboard`, `apt/fuelboard-relay`)
+- [x] Brand logos: proper 2x/3x assets, 75% smaller (315 KB → 79 KB)
+- [x] Security audit (see SECURITY.md)
+- [x] App Store approval gotcha review (see APPSTORE.md)