feat(cctv): add Catalonia (Servei Català de Trànsit) as a keyless CCTV source pack

One WFS/GML XML feed (~135 cameras) aggregating three publishers under a
`font` field: SCT's own highway cameras plus hotlinked Barcelona (IMI) and
Terrassa municipal cameras. Frame URLs are checked against a small host
allowlist rather than one pinned origin, and every non-SCT camera carries
its real owner as a `credit` shown beside the shared provider. The feed
carries no compass heading, so every camera loads at low heading confidence
(same as TfL and Fintraffic), and ground elevation is primed per publisher
rather than one flat prior.

SCT's own frame link needed a workaround: RenderService always 302s to a
second endpoint (TransitCamera) on a Location the upstream hardcodes as
plain http even when requested over https — refused by fetchWithinHost's
same-origin (scheme-included) redirect policy, by design (stops an upstream
steering a host-pinned request into a plaintext downgrade). Separately,
mct.gencat.cat's TLS setup fails the handshake with Node's fetch outright
(ERR_SSL_WRONG_SIGNATURE_TYPE) even though other HTTP clients complete it.
The loader builds the TransitCamera URL itself, over plain http, from
RenderService's sctidcam id, instead of registering the broken upstream
link — the only transport this host actually serves to this runtime.

Verified against the live feed and the production fetch path
(fetchCctvImageFromUpstream): all 135 cameras return real image bytes, 0
false positives. Ambient-card refresh cadence added to src/data/cctvLod.js
(3 minutes), matching the upstream update rate measured empirically (no
change inside 64s, changed within ~90-150s) — the same cadence already used
for Caltrans/TfL/Ontario/TxDOT.

CCTV_CATALONIA_MAX_SOURCES sets the cap and CCTV_CATALONIA_ENABLED=0 turns
the pack off. No overlap with any existing pack (checked catalog.js and the
git history for Spain/Catalonia/Barcelona coverage: none exists).

Verified before this commit: format, check:boundaries, unit suite (3692
tests), and build all green.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

server/providers/cctv/constants.js

@@ -236,6 +236,47 @@ export const CALGARY_DOWNTOWN = { lat: 51.0461, lon: -114.0626 };
  * body cannot be buffered without limit. */
 export const CALGARY_MAX_CATALOG_BYTES = 4 * 1024 * 1024;
 
+/**
+ * Catalonia traffic cameras (Servei Català de Trànsit): one keyless WFS/GML
+ * XML list (verified 2026-09-15, hourly catalog refresh). The feed carries a
+ * `font` field naming the actual publisher per camera — SCT's own highway
+ * cameras plus hotlinked Barcelona (IMI) and Terrassa municipal cameras are
+ * kept, each confirmed to return a real frame. Frame URLs are checked
+ * against a host allowlist rather than one pinned origin, since each
+ * publisher serves from its own host.
+ */
+export const CATALONIA_CAMERAS_URL =
+  'http://www.gencat.cat/transit/opendata/cameres.xml';
+/** Allowed image hosts, one per kept `font` publisher in the feed. */
+export const CATALONIA_IMAGE_HOSTS = Object.freeze(
+  new Set([
+    'mct.gencat.cat', // SCT
+    'www.bcn.cat', // IMI (Ajuntament de Barcelona)
+    'emap.terrassa.cat', // Ajuntament de Terrassa
+  ]),
+);
+/** Per-`font` partner credit, shown beside the provider in the CCTV panel
+ * (same pattern as DriveBC's partner-supplied cameras). SCT is the feed's
+ * own publisher and carries no separate credit. */
+export const CATALONIA_FONT_CREDIT = Object.freeze({
+  IMI: 'Ajuntament de Barcelona',
+  Terrassa: 'Ajuntament de Terrassa',
+});
+/** Ground-elevation priors in metres, by `font`: the feed carries no
+ * elevation, and this pack spans sea level (Barcelona) to Terrassa's plateau
+ * (~270 m). The client's ground snap corrects these on 3D-tile stacks. */
+export const CATALONIA_FONT_ELEVATION_M = Object.freeze({
+  SCT: 80,
+  IMI: 20,
+  Terrassa: 270,
+});
+export const DEFAULT_CATALONIA_MAX_SOURCES = 150;
+/** Prioritization anchors: Barcelona and Terrassa. */
+export const CATALONIA_ANCHORS = [
+  { lat: 41.3874, lon: 2.1686 }, // Barcelona
+  { lat: 41.5636, lon: 2.0111 }, // Terrassa
+];
+
 /** Camera CATALOGS change rarely; 15 min keeps multi-megabyte upstream list refetches (Austin rows.json + 4 Caltrans districts + TfL + Ontario 511) infrequent. Frames are fetched per-request and are unaffected. */
 export const CCTV_SOURCE_CACHE_MS = 15 * 60 * 1000;
 /** Per-provider catalog-fetch timeout. Bounds the worst-case refresh so one