fix(cctv): leave Iceland to its own pack, credit World and Canada packs

Main now ships an Iceland pack that loads the full live Vegagerðin list
(about 500 views) with its CC BY 4.0 credit. The World catalog's 166
Vegagerðin rows point at the same frames under different ids, so every one
of those cameras would be drawn twice. Drop them from the World export and
its loader policy; World is now 2,230 rows and the default catalog limit
7,350 (4,000 shared slots plus 3,350 reserved).

Register Data attribution entries for Ottawa, Québec, TripCheck and MLIT,
as every other CCTV pack has. MLIT's terms ask for the source in the form
"出典：国土交通省 川の防災情報" with the page link, and ODOT asks for
"Camera courtesy of ODOT"; TripCheck partner cameras keep their owner's
name in the label.

The Houston guard test from main checked the old 4,000 default ceiling;
check the 4,000 shared slots instead, like the other pack tests.

scripts/dev-fresh.sh

@@ -44,7 +44,7 @@ CCTV_NSW_ENABLED="${CCTV_NSW_ENABLED:-1}"
 CCTV_NSW_MAX_SOURCES="${CCTV_NSW_MAX_SOURCES:-250}"
 CCTV_CALGARY_ENABLED="${CCTV_CALGARY_ENABLED:-1}"
 CCTV_CALGARY_MAX_SOURCES="${CCTV_CALGARY_MAX_SOURCES:-220}"
-CCTV_MAX_SOURCES="${CCTV_MAX_SOURCES:-7516}"
+CCTV_MAX_SOURCES="${CCTV_MAX_SOURCES:-7350}"
 
 # Capture which provider credentials genuinely came from the parent shell
 # before this launcher resolves dotenv and Keychain fallbacks. Only names are