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]>

docs/CURRENT-STATE.md

@@ -3069,10 +3069,10 @@ its criteria cannot be silently ignored.
 | FIRMS Active Fires ▲   | NASA FIRMS live (VIIRS ×3 NRT + MODIS NRT, trailing 24h)                                                                                                                                        | `src/data/firmsHeatmap.js`                            | `/api/firms` (`FIRMS_MAP_KEY`)                           | 10 min (proxy TTL 30 min)                                                         |
 | Street Level 📷 | Street-level imagery; Mapillary is the first provider (vector tiles, Graph API, MapillaryJS) | `src/layers/streetLevel/` via `src/app/layers/streetLevel.js` | `/api/mapillary/status`, `/api/mapillary/tiles/coverage/{z}/{x}/{y}` (`MAPILLARY_CLIENT_TOKEN`) | camera-driven (320 ms debounce, ≤9 tiles, cached 24 h) |
 | Wind 🌬                 | NOAA GFS 10 m wind (keyless, 0.25°→1° grid; animated particles)                                                                                                                                 | `src/data/wind.js`                                    | `/api/wind`                                              | 1 h (forecast cycle)                                                              |
-| GNSS Interference 📡 | adsb.lol point snapshot, ADS-B NIC/NACp integrity binned per 0.5° cell (gpsjam.org formula and bands, 91.227 NIC/NACp minima, keyless, ODbL) | `src/layers/gnss/` via `src/app/layers/gnss.js` | `/api/gnss-integrity` | 60s (server cache 60 s; 30 min rolling window) |
+| GNSS Integrity 📡 (`gnss-interference`) | adsb.lol point snapshot, low navigation accuracy binned per 0.5° cell (GEV NIC/NACp threshold + gpsjam.org formula and bands, keyless, ODbL) | `src/layers/gnss/` via `src/app/layers/gnss.js` | `/api/gnss-integrity` | 60s (server cache 60 s; 30 min rolling window) |
 | Fire Perimeters 🔥 | NIFC WFIGS current interagency perimeters (keyless, paged past the 2000-record cap); InciWeb catalog + incident page origin and update time checks for verified incident-page links | `src/layers/perimeters/` via `src/app/layers/perimeters.js` | `/api/fire-perimeters` + `/api/fire-perimeters/inciweb/*` | 5 min (server caches: catalog 1 h; publication 30 min) |
 
-GNSS Interference fetches a capped adsb.lol snapshot around the view anchor, keeps each aircraft once per cell over 30 minutes as the camera pans, and draws low/medium/high ground rectangles only for cells with at least 3 aircraft. The row legend counts cells per band. It shows probable interference, not a located emitter.
+GNSS Integrity fetches a capped adsb.lol snapshot around the view anchor, keeps each aircraft once per cell over 30 minutes as the camera pans, and draws low/medium/high ground rectangles only for cells with at least 3 aircraft. The row legend counts cells per band. The method is a GEV threshold plus gpsjam.org aggregation, not the gpsjam method: the per-aircraft rule (NIC < 7 or NACp < 8, borrowed from the US 14 CFR 91.227 ADS-B Out minima, or readsb's GPS-loss flag) and the 30-minute visited-view window are GEV-defined and unvalidated; only the cell formula and 2% / 10% bands come from gpsjam.org. `layer.provenance` (also on `getStats()`) records each part, and the proxy tags its rows with `classifier: gev-nic-nacp-v1`. Cells carry `state: navigation-integrity-anomaly` (medium/high) or `nominal`; `interpretation: suspected-gnss-interference` is a secondary reading, not a detection or a located emitter.
 
 Fire Perimeters uses capped, timed server reads with stale-on-error caching and a per-client limit. Unchanged snapshots retain geometry; link checks cancel on disable or selection change, and the row legend shows reported containment.