chore(catalog-source): split per-source kill switches; default pcat off

Verified 2026-06-01 against dev's 103 unique pcat carIds: the current pcat
dump's deep-scrape (7.978 cars with real parts data via schema_parts or
part_groups+part_group_items) targets a US/JDM-market subset — Toyota 2112,
Nissan 1508, Audi 1311, Chevy 1050, Hyundai 745. **None** of sase's TR-market
vehicles intersect that rich subset:

  - 18/103 sase carIds are in dump.cars at all (registry only)
  - 0/103 yield parts via Bridge A (schema_images → schema_parts)
  - 0/103 yield parts via Bridge B (part_groups → part_group_items)

Even the cars that match by exact carId (Fiat Doblo 368 schemas, Renault
Megane, Bravo 456 schemas) have only diagram metadata — no parts annotation.
The dump scraper finished tier-1 (catalog/model/car listing) and tier-2
(schema diagrams) for these, but stopped before tier-3 (parts annotation).

Under the strict "always correct OEM" constraint there is no safe pcat lookup
today. Disable it. The container stays up for future use cases (OEM cross-
reference search, alt-part matching) and so we can flip the env back without
a code change if a richer dump arrives.

EMEX stays on (its catalog-allowlist is the next step).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker-compose.coolify.yml

@@ -74,6 +74,9 @@ services:
       - CATALOG_SOURCE_DB_ENABLED=${CATALOG_SOURCE_DB_ENABLED:-false}
       - PCAT_SOURCE_DB_URL=${PCAT_SOURCE_DB_URL:-}
       - EMEX_SOURCE_DB_URL=${EMEX_SOURCE_DB_URL:-}
+      # Per-source kill switches. pcat default off (dump doesn't cover TR vehicles).
+      - EMEX_SOURCE_DB_ENABLED=${EMEX_SOURCE_DB_ENABLED:-true}
+      - PCAT_SOURCE_DB_ENABLED=${PCAT_SOURCE_DB_ENABLED:-false}
     depends_on:
       sase-redis:
         condition: service_healthy
@@ -140,6 +143,9 @@ services:
       - CATALOG_SOURCE_DB_ENABLED=${CATALOG_SOURCE_DB_ENABLED:-false}
       - PCAT_SOURCE_DB_URL=${PCAT_SOURCE_DB_URL:-}
       - EMEX_SOURCE_DB_URL=${EMEX_SOURCE_DB_URL:-}
+      # Per-source kill switches. pcat default off (dump doesn't cover TR vehicles).
+      - EMEX_SOURCE_DB_ENABLED=${EMEX_SOURCE_DB_ENABLED:-true}
+      - PCAT_SOURCE_DB_ENABLED=${PCAT_SOURCE_DB_ENABLED:-false}
     depends_on:
       sase-redis:
         condition: service_healthy