feat(cctv): WSDOT highway camera source pack (Washington State)

Adds Washington State's highway cameras as a keyless source pack, from the
Esri JSON layer WSDOT's own Travel Center map consumes
(data.wsdot.wa.gov/travelcenter/Cameras.json, ~1,700 point features).
Closes #624.

- Geometry arrives in EPSG:3857; converted to WGS84 on load and bounded to
  a Washington bounding box.
- Only frames on WSDOT's own images.wsdot.wa.gov host are registered — the
  catalog also lists ~70 partner cameras (Oregon DOT, City of Seattle,
  lodges, airports) whose own terms apply; those are skipped rather than
  proxied. 1,630 cameras survive the filters against the live feed.
- CompassDirection letters (N/E/S/W) give a high-confidence heading; the
  majority `B` ("both directions") rows carry no single facing and use the
  shared id-hash fallback at low confidence, with the usual two pose
  personalities.
- The feed body carries Windows-1252 bytes (en-dashes in titles) with no
  charset declaration, so it is decoded explicitly before parsing.
- WSDOT's layer metadata marks the feed "low volume": the 15-minute catalog
  cache and per-request frame fetches respect that, frames are never stored
  or redistributed, and the WSDOT credit is registered in the attribution
  popover. A keyed WSDOT Traveler Information API serves the same population
  for higher-volume use and is deliberately not required.
- Defaults: 250 cameras nearest Seattle and Spokane; CCTV_WSDOT_MAX_SOURCES
  changes the cap, CCTV_WSDOT_ENABLED=0 turns the pack off.
- Tests: Mercator conversion against a real layer feature, official-host and
  malformed-row filtering, compass mapping and both pose personalities,
  cp1252 decoding, env cap, upstream-failure fallback.

src/data/cctvWsdotSource.test.mjs

@@ -0,0 +1,167 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import {
+  DEFAULT_WSDOT_MAX_SOURCES,
+  WSDOT_CAMERAS_URL,
+} from '../../server/providers/cctv/constants.js';
+import {
+  loadWsdotSourcesFromOpenData,
+  webMercatorToWgs84,
+} from '../../server/providers/cctv/sources.js';
+
+/** Set (or, for `undefined`, delete) environment variables for one test. */
+function withEnv(t, env) {
+  for (const [name, value] of Object.entries(env)) {
+    const previous = process.env[name];
+    t.after(() => {
+      if (previous === undefined) delete process.env[name];
+      else process.env[name] = previous;
+    });
+    if (value === undefined) delete process.env[name];
+    else process.env[name] = value;
+  }
+}
+
+/** Silence the loaders' progress and failure logging. */
+function quiet(t) {
+  t.mock.method(console, 'log', () => {});
+  t.mock.method(console, 'warn', () => {});
+}
+
+/** Web Mercator metres for a WGS84 coordinate (inverse of the loader's math). */
+function mercator(lat, lon) {
+  const R = 6378137;
+  return {
+    x: (lon * Math.PI * R) / 180,
+    y: R * Math.log(Math.tan(Math.PI / 4 + (lat * Math.PI) / 360)),
+  };
+}
+
+/** A `Cameras.json` point feature carrying the fields the loader reads. */
+function wsdotFeature(id, lat, lon, overrides = {}) {
+  const { attributes = {}, geometry } = overrides;
+  return {
+    attributes: {
+      CameraID: id,
+      CameraTitle: `Camera ${id}`,
+      CompassDirection: 'N',
+      ImageURL: `https://images.wsdot.wa.gov/nw/${id}.jpg`,
+      ...attributes,
+    },
+    geometry: geometry === undefined ? mercator(lat, lon) : geometry,
+  };
+}
+
+/** Serialize a payload for the mocked fetch as raw Windows-1252 bytes. */
+function cp1252Response(payload) {
+  const text = JSON.stringify(payload);
+  const bytes = new Uint8Array(text.length);
+  for (let i = 0; i < text.length; i += 1) {
+    const code = text.charCodeAt(i);
+    // U+2013 EN DASH is 0x96 in Windows-1252 — the byte the live feed ships.
+    bytes[i] = code === 0x2013 ? 0x96 : code;
+  }
+  return new Response(bytes, {
+    headers: { 'Content-Type': 'application/json' },
+  });
+}
+
+test('webMercatorToWgs84 recovers WGS84 degrees from layer geometry', () => {
+  // Real feature from the live layer: I-5 at the Interstate Bridge.
+  const { lat, lon } = webMercatorToWgs84(-13656007.102, 5719738.545);
+  assert.ok(Math.abs(lat - 45.62) < 0.05, `lat ${lat}`);
+  assert.ok(Math.abs(lon - -122.675) < 0.05, `lon ${lon}`);
+});
+
+test('WSDOT loader keeps official-host cameras and maps compass directions', async (t) => {
+  quiet(t);
+  withEnv(t, { CCTV_WSDOT_MAX_SOURCES: undefined });
+  const requested = [];
+  t.mock.method(globalThis, 'fetch', async (url) => {
+    requested.push(String(url));
+    return cp1252Response({
+      features: [
+        wsdotFeature(1001, 47.6097, -122.3331, {
+          attributes: {
+            // The 0x2013 below is serialized as the feed's 0x96 byte.
+            CameraTitle: 'I-5 – Seattle, looking south',
+            CompassDirection: 'S',
+          },
+        }),
+        wsdotFeature(9059, 47.66, -117.43, {
+          attributes: { CompassDirection: 'B' },
+        }),
+        // Partner-hosted frame (Oregon DOT): skipped, never proxied.
+        wsdotFeature(1002, 45.62, -122.675, {
+          attributes: {
+            ImageURL: 'https://www.tripcheck.com/RoadCams/cams/bridge.jpg',
+          },
+        }),
+        // Bad rows: non-integer id, missing geometry, out-of-state point.
+        wsdotFeature('1003', 47.6, -122.3),
+        wsdotFeature(1004, 47.6, -122.3, { geometry: null }),
+        wsdotFeature(1005, 34.05, -118.24),
+      ],
+    });
+  });
+
+  const cameras = await loadWsdotSourcesFromOpenData();
+
+  assert.deepEqual(requested, [WSDOT_CAMERAS_URL]);
+  // Exactly the two valid official-host cameras survive; the partner-hosted
+  // frame and the malformed rows are dropped.
+  assert.deepEqual(cameras.map((camera) => camera.id).sort(), [
+    'wsdot-1001',
+    'wsdot-9059',
+  ]);
+
+  const seattle = cameras.find((camera) => camera.id === 'wsdot-1001');
+  assert.equal(seattle.name, 'I-5 – Seattle, looking south');
+  assert.equal(seattle.provider, 'WSDOT');
+  assert.equal(seattle.url, 'https://images.wsdot.wa.gov/nw/1001.jpg');
+  assert.equal(seattle.snapshotUrl, seattle.url);
+  assert.equal(seattle.feedType, 'image');
+  assert.equal(seattle.headingDeg, 180);
+  assert.equal(seattle.headingConfidence, 'high');
+  assert.equal(seattle.fovDeg, 56);
+  assert.ok(Math.abs(seattle.lat - 47.6097) < 0.001);
+  assert.ok(Math.abs(seattle.lon - -122.3331) < 0.001);
+
+  // "Both directions" carries no single facing: id-hash fallback at low
+  // confidence, with the low-confidence pose personality.
+  const spokane = cameras.find((camera) => camera.id === 'wsdot-9059');
+  assert.equal(spokane.headingConfidence, 'low');
+  assert.equal(spokane.fovDeg, 44);
+  assert.ok(spokane.headingDeg >= 0 && spokane.headingDeg < 360);
+});
+
+test('WSDOT loader honors the max-sources cap', async (t) => {
+  quiet(t);
+  withEnv(t, { CCTV_WSDOT_MAX_SOURCES: '8' });
+  const features = [];
+  for (let i = 0; i < 24; i += 1) {
+    features.push(wsdotFeature(2000 + i, 47.0 + i * 0.05, -122.9 + i * 0.05));
+  }
+  t.mock.method(globalThis, 'fetch', async () => cp1252Response({ features }));
+
+  const cameras = await loadWsdotSourcesFromOpenData();
+  assert.equal(cameras.length, 8);
+});
+
+test('WSDOT loader defaults its cap and survives upstream failure', async (t) => {
+  quiet(t);
+  withEnv(t, { CCTV_WSDOT_MAX_SOURCES: undefined });
+  assert.equal(DEFAULT_WSDOT_MAX_SOURCES, 250);
+
+  t.mock.method(
+    globalThis,
+    'fetch',
+    async () => new Response('', { status: 503 }),
+  );
+  assert.deepEqual(await loadWsdotSourcesFromOpenData(), []);
+
+  t.mock.method(globalThis, 'fetch', async () => {
+    throw new Error('network down');
+  });
+  assert.deepEqual(await loadWsdotSourcesFromOpenData(), []);
+});

src/data/dataCredits.js

@@ -293,6 +293,16 @@ export const DATA_CREDITS = [
       '<a href="https://www2.gov.bc.ca/gov/content/data/open-data/open-government-licence-bc" target="_blank" rel="noopener">Open Government Licence – British Columbia</a>. ' +
       'Some cameras are supplied by partners (TransLink, the City of Vancouver, the City of Surrey, Parks Canada and others); each names its provider in the CCTV panel.',
   },
+  {
+    key: 'wsdot-cctv',
+    html:
+      'CCTV cameras &amp; frames (Washington State): ' +
+      '<a href="https://wsdot.wa.gov/" target="_blank" rel="noopener">Washington State Department of Transportation</a> ' +
+      '(<a href="https://wsdot.com/travel/real-time/cameras" target="_blank" rel="noopener">Travel Center</a>), ' +
+      'used per the ' +
+      '<a href="https://wsdot.wa.gov/about/policies/travel-information-disclaimer" target="_blank" rel="noopener">WSDOT travel information disclaimer</a> ' +
+      '(low-volume public feed; catalog cached, frames proxied on demand)',
+  },
   {
     key: 'tallinn-cctv',
     html: