zircuit-garfield: migrate testnet to Conduit (op-reth + op-node)

Replace the old op-geth + zircuit1/op-node garfield (holesky L1, built-in
OP_NODE_NETWORK=garfield) with the Conduit node template:
- EL: ghcr.io/conduitxyz/conduit-op-reth:v2.1.1 (--chain=/config/genesis.json)
- CL: us-docker.pkg.dev/oplabs-tools-artifacts/images/op-node:v1.19.0
      (OP_NODE_ROLLUP_CONFIG=/config/rollup.json)
- L1: Ethereum Sepolia (l1_chain_id 11155111)
- rollup.json/genesis.json from api.conduit.xyz (slug zircuit-garfield-testnet;
  regenesis 2026-07-06, bedrockBlock 0)
- Conduit P2P static peer + bootnodes
Remove the 4 now-orphaned op-geth garfield composes (none were deployed).

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

compose_registry.json

@@ -8470,6 +8470,22 @@
       "xlayer-testnet-op-reth-archive-trace"
     ]
   },
+  {
+    "chain": "garfield",
+    "client": "reth",
+    "compose_file": "op/reth/zircuit-garfield-op-reth-pruned-trace",
+    "features": [
+      "trace"
+    ],
+    "network": "zircuit",
+    "node": "node",
+    "relay": null,
+    "stack": "op",
+    "type": "pruned",
+    "volumes": [
+      "zircuit-garfield-op-reth-pruned-trace"
+    ]
+  },
   {
     "chain": "mainnet",
     "client": "reth",