fix(transit): read Rio speeds as the m/s SMTR publishes

Both SMTR feeds now publish Position.speed in m/s. Compared with how far
vehicles moved between reports on 2026-11-05, the published values ran
3.1x (buses) and 3.6x (BRT) below the observed speed, so the km/h
conversion divided real speeds by 3.6. Drop speedUnit and the conversion.

DATA_SOURCES.md

@@ -98,7 +98,7 @@ How to read this:
 | **Barrie Transit** (myridebarrie.ca) | Transit layer live vehicles, Barrie ON | Barrie Transit realtime data, published by the City of Barrie under a licence accepted by use of the data. The licence is revocable and requires no attribution. | Courtesy credit to the City of Barrie (the licence requires none, and its trademark clause is broad) |
 | **YRT/Viva** (rtu.york.ca) | Transit layer live vehicles, York Region ON | York Region Transit realtime data, first-party York Region infrastructure under the YRT Open Data Licence v2.0, which permits commercial use and makes attribution optional. Viva route ids are named by colour from York Region’s published GTFS. | "Contains public transit Information made available under YRT’s Open Data Licence" — the licence’s own wording, given though not required |
 | **Burlington Transit** (opendata.burlington.ca) | Transit layer live vehicles, Burlington ON | Burlington Transit realtime data under the City of Burlington Open Data Terms of Use, which permit any lawful purpose. The terms are revocable and must travel with the data, so the credit links them. Route ids are internal keys and are joined to the City’s published GTFS. | Credit to the City of Burlington plus a link to its Open Data Terms of Use, which the licence requires |
-| **SMTR Rio de Janeiro** (dados.mobilidade.rio) | Transit layer live vehicles, Rio de Janeiro: municipal buses (SPPO) and the Mobi-Rio BRT, as two feeds | CC BY 4.0, stated on both data.rio catalog pages. Keyless GTFS-Realtime published by the Secretaria Municipal de Transportes, labelled beta, with a gateway limit of 5 requests a second and 60 a minute. Speeds arrive in km/h rather than m/s and are converted by the proxy. Route ids are internal keys and are joined to the line names in SMTR’s published GTFS `routes.txt` (dados.mobilidade.rio/gtfs/schedule), under the same CC BY 4.0 terms. | Attribution to SMTR / Prefeitura da Cidade do Rio de Janeiro under CC BY 4.0 |
+| **SMTR Rio de Janeiro** (dados.mobilidade.rio) | Transit layer live vehicles, Rio de Janeiro: municipal buses (SPPO) and the Mobi-Rio BRT, as two feeds | CC BY 4.0, stated on both data.rio catalog pages. Keyless GTFS-Realtime published by the Secretaria Municipal de Transportes, labelled beta, with a gateway limit of 5 requests a second and 60 a minute. Route ids are internal keys and are joined to the line names in SMTR’s published GTFS `routes.txt` (dados.mobilidade.rio/gtfs/schedule), under the same CC BY 4.0 terms. | Attribution to SMTR / Prefeitura da Cidade do Rio de Janeiro under CC BY 4.0 |
 | **Radio Browser**                                                     | Geolocated internet-radio station directory and station-level tags                                                                  | Public-domain directory data under PDDL 1.0; individual broadcaster stream terms apply                                                                                                                                                                                                                                                                | "Radio Browser" plus a link to the selected broadcaster                                                                                     |
 | **Re:Earth Terrain** (Mapterhorn)                                     | Terrain (keyless globe stacks — OSM etc. — + `/api/terrain/heights` ellipsoidal-height lookups)                                     | Terrain mesh: CC BY 4.0; geoid: EGM2008 (NGA, public domain)                                                                                                                                                                                                                                                                                          | "Terrain (keyless globe stacks): Re:Earth Terrain / Mapterhorn (CC BY 4.0) / EGM2008 (NGA)"                                                 |
 | **OpenSeaMap** (`tiles.openseamap.org`) | Sea Marks layer: raster overlay of buoys, lighthouses and ports (#10) | Chart tiles CC BY-SA 2.0; data ODbL 1.0 via OpenStreetMap | "Sea marks © OpenSeaMap contributors (CC BY-SA 2.0) · Data © OpenStreetMap contributors (ODbL)" |