op/doma/testnet: add Celestia Alt-DA support (celestiaorg/op-alt-da:v0.15.0)

- Add relay template (templates/relays/celestia.doma.yml) for op-alt-da
- Add celestia relay config to op/doma stack in context.yml
- Add relay: celestia to op/doma testnet in config.yml
- Add op-node.doma.yml template with ALTDA env vars gated on relay_name
- Update op/doma/testnet/rollup.json with complete config including alt_da block

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

op/doma/testnet/rollup.json

@@ -13,7 +13,11 @@
       "batcherAddr": "0x7bff49d5c9ba8e518061f4978e8ff0920eaa3a7c",
       "overhead": "0x00000000000000000000000000000000000000000000000000000000000000bc",
       "scalar": "0x0000000000000000000000000000000000000000000000000000000000010b30",
-      "gasLimit": 30000000
+      "gasLimit": 30000000,
+      "eip1559Params": "0x0000000000000000",
+      "operatorFeeParams": "0x0000000000000000000000000000000000000000000000000000000000000000",
+      "daFootprintGasScalar": 0,
+      "minBaseFee": 0
     }
   },
   "block_time": 2,
@@ -27,6 +31,11 @@
   "delta_time": 0,
   "ecotone_time": 0,
   "fjord_time": 0,
+  "granite_time": 1744729200,
+  "holocene_time": 1744822800,
+  "isthmus_time": 1744905600,
+  "jovian_time": 1768978801,
+  "pectra_blob_schedule_time": 1742486400,
   "batch_inbox_address": "0x7a666bec1e5ea04f832a03edd36516dcc04f8712",
   "deposit_contract_address": "0x330c5f4dbe72ac987015d3dd390eba3b25968b1c",
   "l1_system_config_address": "0xa6378952eb60076ac26546c02c93d32b38f8655e",
@@ -37,8 +46,10 @@
     "eip1559Denominator": 50,
     "eip1559DenominatorCanyon": 250
   },
-  "granite_time": 1744729200,
-  "holocene_time": 1744822800,
-  "isthmus_time": 1744905600,
-  "jovian_time": 1768978801
+  "alt_da": {
+    "da_commitment_type": "GenericCommitment",
+    "da_challenge_contract_address": "0x0000000000000000000000000000000000000000",
+    "da_challenge_window": 1,
+    "da_resolve_window": 1
+  }
 }