deploy: mainnet bring-up patches (env-override genesis + host/network)

shared: VECTOR_ZERO_TIME now reads VECTOR_ZERO_TIME_MS from env, defaults
to testnet genesis (1_752_057_484_000 ms). Mainnet deploys set
VECTOR_ZERO_TIME_MS=1756485600000. Existing testnet deployments unaffected
since env unset → testnet default. Patched in both lucidContext.ts (lucid
slot config override) and liveCbor.ts buildLiveTxForSubmit (submitted_at
slot-alignment).

deploy/mainnet: buyer host changed mp.vector.* → marketplace.vector.* per
operator-owned DNS. Indexer compose drops apex-net network (we point at
the hosted mainnet ogmios over public WSS, not via apex-dashboard-mainnet
which is not deployed on this box).

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

deploy/mainnet/docker-compose.buyer.yml

@@ -36,7 +36,7 @@ services:
       - "traefik.enable=true"
       - "traefik.docker.network=dashboard_default"
       - "traefik.http.routers.mp-buyer-mainnet.entrypoints=web"
-      - "traefik.http.routers.mp-buyer-mainnet.rule=Host(`mp.vector.apexfusion.org`)"
+      - "traefik.http.routers.mp-buyer-mainnet.rule=Host(`marketplace.vector.apexfusion.org`)"
       - "traefik.http.services.mp-buyer-mainnet.loadbalancer.server.port=8070"
     logging:
       driver: json-file

deploy/mainnet/docker-compose.indexer.yml

@@ -34,7 +34,6 @@ services:
       start_period: 20s
     networks:
       - marketplace-mainnet-net
-      - apex-net
       - traefik-net
     labels:
       - "traefik.enable=true"
@@ -52,9 +51,6 @@ networks:
   marketplace-mainnet-net:
     external: true
     name: marketplace-mainnet-net
-  apex-net:
-    external: true
-    name: apex-dashboard-mainnet_mainnet-net
   traefik-net:
     external: true
     name: dashboard_default