fix(cctv): make the Lithuania pack opt-in until its licence is confirmed

The camera endpoints are the eismoinfo.lt website backend, which the Via
Lietuva open-data statement does not list, so the pack now follows the NYC
opt-in pattern (CCTV_LITHUANIA_ENABLED=1) and the docs say why. A failed
catalog request now aborts its sibling instead of leaving it open until the
timeout, and a redirect is logged as not followed.

docs/CURRENT-STATE.md

@@ -981,7 +981,10 @@ round-robin, so adding this pack does not silently drop another region.
 
 ## Lithuania CCTV source pack
 
-The CCTV catalog includes Via Lietuva / Eismoinfo road cameras by default.
+The CCTV catalog can include Via Lietuva / Eismoinfo road cameras. The pack is
+off unless `CCTV_LITHUANIA_ENABLED=1`, because its camera endpoints are the
+eismoinfo.lt website backend rather than a service listed in Via Lietuva's
+open-data statement, so the licence for the photos is unconfirmed.
 Two keyless public endpoints provide current snapshot URLs and WGS84 camera
 locations; records are joined by ID, with invalid coordinates and off-origin
 image URLs rejected. Catalog requests refuse redirects, have a 15-second
@@ -990,7 +993,6 @@ and fair catalog allocation. An unavailable source contributes an empty pack.
 Frames use the registered-image proxy and retain Via Lietuva attribution.
 The images are periodically updated road-condition photographs, not continuous
 video; camera poses use the existing low-confidence heading prior.
-`CCTV_LITHUANIA_ENABLED=0` disables the pack, and
 `CCTV_LITHUANIA_MAX_SOURCES` sets its cap (default 400, bounded to 1–1000).
 
 ## DriveBC CCTV source pack