fix(cctv): raise the default catalog cap to 4,500 and enforce it over every pack

The per-pack defaults already summed to 4,054 before WSDOT (4,304 with
it), past the documented 4,000 cap, so a default install was trimming.
The existing sum check in the DriveBC test listed packs by hand and
missed Calgary and DelDOT. Replace it with a check in
cctvCatalogCap.test.mjs that sums every exported DEFAULT_*_MAX_SOURCES,
and drop the Calgary test that pinned the cap at exactly 4,000.

.env.example

@@ -182,6 +182,6 @@ AISSTREAM_API_KEY=
 # CCTV_CALGARY_ROWS_URL=                               # override the Open Calgary catalog URL
 # CCTV_WSDOT_ENABLED=1                                 # set 0 to disable the WSDOT (Washington State) highway cameras
 # CCTV_WSDOT_MAX_SOURCES=250                           # cap cameras loaded from the WSDOT catalog, nearest Seattle/Spokane first
-# CCTV_MAX_SOURCES=4000                                # catalog-wide ceiling, shared round-robin across packs
+# CCTV_MAX_SOURCES=4500                                # catalog-wide ceiling, shared round-robin across packs
 # CCTV_PREFER_AUSTIN=1                                 # prioritize Austin cameras in the registry
 # CCTV_FORCE_AUSTIN=                                   # force live default sources when a source-pack JSON is configured