katana-mainnet: use custom genesis/rollup config

Katana is not in the OP Stack superchain registry, so it needs
custom genesis.json and rollup.json files instead of the built-in
network name. Follows the same pattern as superseed-mainnet.

Changes:
- Remove GETH_OP_NETWORK env var
- Add genesis init in entrypoint (checks if /data/geth exists)
- Add --networkid=747474
- Mount op/katana/mainnet as /config in both geth and op-node
- Replace OP_NODE_NETWORK with OP_NODE_ROLLUP_CONFIG

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

op/geth/katana-mainnet-op-geth-pruned-pebble-path.yml

@@ -50,11 +50,10 @@ services:
       - 6060
       - 8551
     environment:
-      - GETH_OP_NETWORK=katana-mainnet
       - GETH_OVERRIDE_ISTHMUS=1746806401
       - GETH_ROLLUP_DISABLETXPOOLGOSSIP=true
       - GETH_ROLLUP_SEQUENCERHTTP=https://rpc.katana.network
-    entrypoint: /bin/sh -c 'exec geth "$@"' --
+    entrypoint: /bin/sh -c '[ ! -d /data/geth ] && geth --db.engine=pebble --gcmode=full --datadir /data init --state.scheme=path /config/genesis.json; exec geth "$@"' --
     command:
       - --datadir=/data
       - --db.engine=pebble
@@ -63,6 +62,7 @@ services:
       - --metrics
       - --metrics.addr=0.0.0.0
       - --metrics.port=6060
+      - --networkid=747474
       - --nodiscover
       - --rpc.gascap=600000000
       - --rpc.txfeecap=0
@@ -87,6 +87,7 @@ services:
       - chains
     volumes:
       - ${KATANA_MAINNET_OP_GETH_PRUNED_PEBBLE_PATH_DATA:-katana-mainnet-op-geth-pruned-pebble-path}:/data
+      - ./op/katana/mainnet:/config
       - .jwtsecret:/jwtsecret:ro
       - /slowdisk:/slowdisk
     logging: *logging-defaults
@@ -121,7 +122,7 @@ services:
       - OP_NODE_METRICS_ADDR=0.0.0.0
       - OP_NODE_METRICS_ENABLED=true
       - OP_NODE_METRICS_PORT=7300
-      - OP_NODE_NETWORK=katana-mainnet
+      - OP_NODE_ROLLUP_CONFIG=/config/rollup.json
       - OP_NODE_P2P_ADVERTISE_IP=${IP}
       - OP_NODE_P2P_LISTEN_IP=0.0.0.0
       - OP_NODE_P2P_LISTEN_TCP_PORT=19009
@@ -140,6 +141,7 @@ services:
     networks:
       - chains
     volumes:
+      - ./op/katana/mainnet:/config
       - .jwtsecret:/jwtsecret:ro
     logging: *logging-defaults
     labels: