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>

op/zircuit/garfield/rollup.json

@@ -0,0 +1,44 @@
+{
+  "genesis": {
+    "l1": {
+      "hash": "0x2745f2ee5ef635c8b9e0a4a383b3d8544a33af944949d1c2a3a41ed6389d42be",
+      "number": 11215627
+    },
+    "l2": {
+      "hash": "0x5df56d01742c450205b4afb7f169c6723254d671becabd1f5a144eb8a3e3edbd",
+      "number": 21503691
+    },
+    "l2_time": 1783343862,
+    "system_config": {
+      "batcherAddr": "0xc2393cf891b20400d66355b943cc35972b234a64",
+      "overhead": "0x0000000000000000000000000000000000000000000000000000000000000000",
+      "scalar": "0x010000000000000000000000000000000000000000000000000d273000001db0",
+      "gasLimit": 30000000,
+      "eip1559Params": "0x0000000000000000",
+      "operatorFeeParams": "0x0000000000000000000000000000000000000000000000000000000000000000"
+    }
+  },
+  "block_time": 2,
+  "max_sequencer_drift": 1800,
+  "seq_window_size": 3600,
+  "channel_timeout": 300,
+  "l1_chain_id": 11155111,
+  "l2_chain_id": 48898,
+  "regolith_time": 0,
+  "canyon_time": 0,
+  "delta_time": 0,
+  "ecotone_time": 0,
+  "fjord_time": 0,
+  "granite_time": 0,
+  "holocene_time": 0,
+  "isthmus_time": 0,
+  "batch_inbox_address": "0xff00000000000000000000000000000000048898",
+  "deposit_contract_address": "0x4e21a71ac3f7607da5c06153a17b1dd20e702c21",
+  "l1_system_config_address": "0x3d3fc87ec70705ba6fddacc72d5c71440f64463f",
+  "protocol_versions_address": "0x0000000000000000000000000000000000000000",
+  "chain_op_config": {
+    "eip1559Elasticity": 6,
+    "eip1559Denominator": 50,
+    "eip1559DenominatorCanyon": 250
+  }
+}