feat(transit): add Rio de Janeiro buses and BRT (SMTR GTFS-RT, CC BY 4.0)

Register Rio's two keyless GTFS-Realtime VehiclePositions feeds from the
city transport secretariat (SMTR): municipal buses (SPPO) and the
Mobi-Rio BRT, the Transit layer's first Latin American region.

Both feeds publish Position.speed in km/h instead of m/s. A new optional
registry field, speedUnit: 'kmh', makes buildTransitSnapshot convert it
once, so every speedMps consumer stays correct and other feeds are
untouched.

Document the source in DATA_SOURCES.md and update the region lists in
README.md and docs/CURRENT-STATE.md.

Refs #1480

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/data/transitFeeds.js

@@ -385,7 +385,12 @@ function burlingtonRouteLabel(routeId) {
  *   url: string, headers?: Record<string, string>,
  *   license: string, licenseUrl: string, attribution: string,
  *   defaultMode: string, routeMode?: (routeId: string|null) => string,
+ *   speedUnit?: 'kmh',
  * }>>}
+ *
+ * `speedUnit: 'kmh'` marks a feed that publishes `Position.speed` in km/h
+ * instead of the m/s the spec requires; the proxy converts it before anything
+ * downstream reads `speedMps`.
  */
 export const TRANSIT_FEED_REGISTRY = Object.freeze([
   Object.freeze({
@@ -729,6 +734,51 @@ export const TRANSIT_FEED_REGISTRY = Object.freeze([
     defaultMode: 'bus',
     routeLabel: burlingtonRouteLabel,
   }),
+  Object.freeze({
+    id: 'smtr-rio-onibus',
+    name: 'Rio buses (SPPO)',
+    operator: 'Secretaria Municipal de Transportes (SMTR), Rio de Janeiro',
+    region: 'Rio de Janeiro, RJ',
+    // Every vehicle in a 2026-10-29 snapshot, from Santa Cruz in the west to
+    // the Zona Sul, sat within 31 km of this point.
+    center: Object.freeze({ lat: -22.92, lon: -43.42 }),
+    loadRadiusKm: 45,
+    url: 'https://dados.mobilidade.rio/gtfs/realtime/onibus/vehicle-positions',
+    license: 'CC BY 4.0',
+    licenseUrl:
+      'https://www.data.rio/documents/997bc16cc4344a5cb0e48ab06cbdfd1f',
+    attribution: 'SMTR / Prefeitura da Cidade do Rio de Janeiro (CC BY 4.0)',
+    defaultEnabled: true,
+    terms: Object.freeze({
+      quote:
+        'This work is licensed under a Creative Commons Attribution 4.0 International License',
+      note: 'The data.rio catalog page labels the feed [beta] and states a gateway limit of 5 requests a second and 60 a minute behind a 10-second cache, which the 15-second proxy TTL stays inside. It is the named replacement for the JSON GPS endpoints SMTR deprecated on 2026-10-07 and says it will switch off by 2026-11-30. SMTR relays the concessionaires’ ITS data and repairs trips with its own matching; the page places accuracy with the suppliers. Speeds arrive in km/h, not m/s (a 2026-10-29 snapshot peaked at 89), hence `speedUnit`. Route ids are internal keys: `O0313AAA0A` carried service 313 in the same day’s JSON feed. They are shown raw until a published table is joined.',
+    }),
+    defaultMode: 'bus',
+    speedUnit: 'kmh',
+  }),
+  Object.freeze({
+    id: 'smtr-rio-brt',
+    name: 'Mobi-Rio BRT',
+    operator:
+      'Secretaria Municipal de Transportes (SMTR), Rio de Janeiro, for the Mobi-Rio BRT fleet',
+    region: 'Rio de Janeiro, RJ',
+    center: Object.freeze({ lat: -22.92, lon: -43.42 }),
+    loadRadiusKm: 45,
+    url: 'https://dados.mobilidade.rio/gtfs/realtime/brt/vehicle-positions',
+    license: 'CC BY 4.0',
+    licenseUrl:
+      'https://www.data.rio/documents/8bb196cc02174d25b77437bb2f6443d4',
+    attribution: 'SMTR / Prefeitura da Cidade do Rio de Janeiro (CC BY 4.0)',
+    defaultEnabled: true,
+    terms: Object.freeze({
+      quote:
+        'This work is licensed under a Creative Commons Attribution 4.0 International License',
+      note: 'Same catalog terms, [beta] label and gateway limits as the bus feed. The fleet is operated by Mobi-Rio and tracked by SONDA, whose data SMTR relays. Speeds are km/h here too (peak 62 in the same snapshot). Route ids are opaque (`20000461130`) and are shown raw.',
+    }),
+    defaultMode: 'bus',
+    speedUnit: 'kmh',
+  }),
 ]);
 
 /**