fix(gnss): separate GEV integrity classifier from GPSJAM aggregation; machine-readable provenance

Review on #855: the per-aircraft rule (NIC < 7 || NACp < 8, borrowed from
the US 14 CFR 91.227 ADS-B Out minima) is GEV-defined, not gpsjam's, and
gpsjam's map shows low navigation accuracy, not necessarily jamming.

- Primary cell state is now `navigation-integrity-anomaly` (medium/high) or
  `nominal`; `suspected-gnss-interference` is a secondary `interpretation`
  marked validated: false.
- GNSS_PROVENANCE / gnssProvenance({ windowMs }) records the classifier
  (gev-nic-nacp-v1, GEV, unvalidated), the gpsjam aggregation (formula,
  bands [0.02, 0.1], FAQ source) and the GEV 30-minute visited-view window,
  built from the constants the code applies. Exposed as layer.provenance
  and getStats().provenance; the proxy tags responses with `classifier`.
- Visible name "GNSS Integrity", legend "... low accuracy", blurb leads with
  low navigation accuracy and states the threshold is a GEV choice.
- Layer id `gnss-interference` and share token `0` unchanged.
- Voice aliases add "gnss integrity", "navigation integrity",
  "low navigation accuracy"; the interference aliases stay.
- Docs describe the method as GEV threshold + gpsjam aggregation.
- Tests: provenance object, renamed state/label, proxy classifier tag;
  qa-gnss asserts provenance and wording in the real app.

Hex project - Crew Leo Agile dev team.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

DATA_SOURCES.md

@@ -25,7 +25,7 @@ How to read this:
 | **OpenStreetMap** | Map and place data (roads, military areas and names, ALPR, place search, outlines); via vector tiles, hourly ALPR extract, bundled data, Nominatim and optional self-configured Overpass | [ODbL 1.0](https://opendatacommons.org/licenses/odbl/1-0/) | © OpenStreetMap contributors |
 | **Google Map Tiles API** (Photorealistic 3D Tiles) + Places/Geocoding | The 3D globe, voice scene context, and on-demand nearby installation search                                                         | Google Maps Platform ToS (proprietary, your own key + billing)                                                                                                                                                                                                                                                                                        | "Google" / "Google Maps" logo — **shown in-app**, required                                                                                  |
 | **OpenSky Network**                                                   | Primary worldwide live-flight snapshot                                                                                              | Non-commercial research/education license                                                                                                                                                                                                                                                                                                             | Schäfer et al., _"Bringing Up OpenSky"_, IPSN 2014 + opensky-network.org                                                                    |
-| **adsb.lol point API**                                                | Bounded live-flight fallback when OpenSky has no usable snapshot; GNSS Interference layer (per-aircraft NIC/NACp integrity only, via `/api/gnss-integrity`, 60 s server cache)                                                                    | ODbL 1.0                                                                                                                                                                                                                                                                                                                                              | adsb.lol contributors; `api.adsb.lol/v2/lat/{lat}/lon/{lon}/dist/{radius}`                                                                  |
+| **adsb.lol point API**                                                | Bounded live-flight fallback when OpenSky has no usable snapshot; GNSS Integrity layer (per-aircraft NIC/NACp integrity only, via `/api/gnss-integrity`, 60 s server cache)                                                                    | ODbL 1.0                                                                                                                                                                                                                                                                                                                                              | adsb.lol contributors; `api.adsb.lol/v2/lat/{lat}/lon/{lon}/dist/{radius}`                                                                  |
 | **adsb.lol**                                                          | Military flights + aircraft traces                                                                                                  | ODbL 1.0                                                                                                                                                                                                                                                                                                                                              | "adsb.lol" (ODbL)                                                                                                                           |
 | **adsbdb** (`api.adsbdb.com`) | Aircraft type, model name and registration by ICAO hex for enriched flights; airline and origin/destination airports for the tracked flight's callsign | No licence or rate limit is published for the service. Its own credits: aircraft data from PlaneBase, ICAO-to-N-number conversion by Guillaume Michel, and flight route data that "is the work of David Taylor, Edinburgh and Jim Mason, Glasgow, and may not be copied, published, or incorporated into other databases without the explicit permission of David J Taylor, Edinburgh" | "adsbdb — api.adsbdb.com" (courtesy); route data credited to David Taylor, Edinburgh, and Jim Mason, Glasgow |
 | **AISStream.io**                                                      | Live vessels (AIS)                                                                                                                  | Free, beta, no formal ToS; AIS is a public broadcast                                                                                                                                                                                                                                                                                                  | "AISStream.io" (courtesy)                                                                                                                   |
@@ -78,7 +78,7 @@ The optional Local ADS-B layer and the broadcast-FM receiver use radio you recei
 - **Google Maps Platform.** You supply your own API key and are bound by [Google's ToS](https://cloud.google.com/maps-platform/terms). Google Maps Content (tiles, geocodes, places) **may not be cached, stored, rehosted, or committed** — this app only ever uses it live, which is the compliant pattern. The "Google" attribution is displayed on the globe and must stay visible. Restrict your key (see [SECURITY.md](SECURITY.md)).
 - **OpenSky Network.** Its license is **non-commercial**, and operational use of the REST API in a live product can require a prior written agreement with OpenSky — even for non-profit/government use. If you deploy this commercially, contact OpenSky for your own terms. The flights layer is a toggle and runs anonymously by default.
 - **adsb.lol flight fallback.** When OpenSky is unavailable and no last-good OpenSky response exists, the server requests a cached, capped 250 nm adsb.lol point snapshot around the current camera subpoint. This is regional observed context, not worldwide completeness; provenance is exposed in the Flights stats/context row. Military ICAOs remain reconciled through the existing dedicated military registry rather than duplicated.
-- **GNSS interference (adsb.lol integrity fields).** The GNSS Interference layer reads the same keyless 250 nm point snapshot around the camera (anchor rounded to a whole degree, 60 s server cache, cooldown on upstream 429). The server returns only hex, position, NIC, NACp and readsb's GPS-loss flag for airborne ADS-B v1/v2 transponder positions seen in the last minute; callsigns and registrations are dropped. An aircraft is degraded when it reports below the 14 CFR 91.227(c) ADS-B Out minima (NIC < 7 or NACp < 8) or readsb flags GPS loss; cells use gpsjam.org's published formula and bands (`100 × (bad − 1) / total`; low < 2 %, medium 2–10 %, high > 10 %; at least 3 aircraft per 0.5° cell over a rolling 30-minute window). Degraded navigation accuracy indicates probable jamming or spoofing, not a confirmed source or location. Verified 2026-09-29.
+- **GNSS integrity (adsb.lol integrity fields).** The GNSS Integrity layer (id `gnss-interference`) reads the same keyless 250 nm point snapshot around the camera (anchor rounded to a whole degree, 60 s server cache, cooldown on upstream 429). The server returns only hex, position, NIC, NACp and readsb's GPS-loss flag for airborne ADS-B v1/v2 transponder positions seen in the last minute; callsigns and registrations are dropped. The method has three separately sourced parts, exposed as machine-readable `provenance` on the layer and its stats: (1) a GEV-defined per-aircraft classifier (`gev-nic-nacp-v1`): an aircraft has low navigation accuracy when it reports NIC < 7 or NACp < 8 or readsb flags GPS loss. The numbers are borrowed from the 14 CFR 91.227(c) ADS-B Out performance minima, a US regulation, not a published interference classifier; gpsjam.org does not publish its per-aircraft threshold ([FAQ](https://gpsjam.org/faq)), and this one is not yet validated against known events. (2) gpsjam.org's published cell formula and bands (`100 × (bad − 1) / total`; low < 2 %, medium 2–10 %, high > 10 %). (3) A GEV-defined window: at least 3 aircraft per 0.5° cell over a rolling 30 minutes around the views the user visits. Medium and high cells are navigation-integrity anomalies. Suspected jamming or spoofing is a secondary interpretation, not a confirmed source or location: avionics faults also report low values. Verified 2026-09-29.
 - **adsbdb enrichment.** `/api/adsbdb` resolves an ICAO hex to aircraft type, model name and registration, and the tracked flight's callsign to an airline and an origin/destination pair. Fan-out is deliberately small because adsbdb is a free community API that publishes no quota: at most 4 requests in flight, dispatches dripped to roughly 5/s, and each key asked for at most once per session, with route lookups reserved for the tracked aircraft. The dev-server proxy caches each key for 24 hours in `.gev-cache/adsbdb.json`, negative answers included, so fresh entries survive server restarts. That gitignored cache remains local to the deployment and is not bundled with this repo. adsbdb publishes no general service license; its README says the route data may not be copied, published, or incorporated into other databases without the explicit permission of David J Taylor, Edinburgh. Deployers are responsible for obtaining any permission their use requires. Enrichment is best-effort and fail-silent — a flight that gets no answer keeps what the flight feed already gave it.
 - **Launch Library 2.** `/api/launches` makes a server-side rolling-30-day query against the supported v2.3 detailed launch endpoint, caches successful responses for 15 minutes in memory and on disk, and serves the last successful response during a throttle or transient outage. Anonymous access is limited to 15 calls/hour; deployments can provide `LL2_API_TOKEN` for authenticated access. The Space Devs' published terms permit using and sharing the API data in any form, ask users not to forward it without adding value, disclaim complete accuracy, and encourage—but do not require—attribution. This app keeps a courtesy credit. Payload and stage/recovery records are shown only when supplied. Failed launches expose their source status and never receive fallback orbit geometry or a live/estimated marker. LL2 supplies launch context and event timing, not continuous ascent telemetry or live orbital state.
 - **TfL JamCams.** The camera list comes from the keyless `api.tfl.gov.uk` endpoint (an optional `TFL_APP_KEY` raises its rate limit); frames come from TfL's public S3 bucket. The "Powered by TfL Open Data" attribution is required by TfL's terms and is registered in the Data attribution popover.