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]>

src/data/dataCredits.js

@@ -104,7 +104,7 @@ export const DATA_CREDITS = [
   {
     key: 'adsblol',
     html:
-      'Military flights, aircraft traces, bounded regional flight fallback & GNSS interference: ' +
+      'Military flights, aircraft traces, bounded regional flight fallback & GNSS navigation integrity: ' +
       '<a href="https://adsb.lol" target="_blank" rel="noopener">adsb.lol</a> ' +
       '(ODbL 1.0)',
   },