[docs-agent] UTXO API: hardcode chain-specific server URLs (no network dropdown)

src/openapi/utxo-bitcoincash/utxo-bitcoincash.yaml

@@ -9,13 +9,8 @@ info:
     Bitcoin Cash networks. The same paths are available on every UTXO chain Alchemy supports —
     switch chains using the chain-specific overview pages or by changing the host.
 servers:
-  - url: https://{network}.g.alchemy.com/v2
-    variables:
-      network:
-        default: bitcoincash-mainnet
-        enum:
-          - bitcoincash-mainnet
-          - bitcoincash-testnet
+  - url: https://bitcoincash-mainnet.g.alchemy.com/v2
+    description: Bitcoin Cash mainnet
 paths:
   "/{apiKey}/api/v2/block-index/{block_height}":
     get:

src/openapi/utxo-dogecoin/utxo-dogecoin.yaml

@@ -9,12 +9,8 @@ info:
     Dogecoin. The same paths are available on every UTXO chain Alchemy supports — switch chains
     using the chain-specific overview pages or by changing the host.
 servers:
-  - url: https://{network}.g.alchemy.com/v2
-    variables:
-      network:
-        default: dogecoin-mainnet
-        enum:
-          - dogecoin-mainnet
+  - url: https://dogecoin-mainnet.g.alchemy.com/v2
+    description: Dogecoin mainnet
 paths:
   "/{apiKey}/api/v2/block-index/{block_height}":
     get:

src/openapi/utxo-litecoin/utxo-litecoin.yaml

@@ -9,13 +9,8 @@ info:
     Litecoin networks. The same paths are available on every UTXO chain Alchemy supports —
     switch chains using the chain-specific overview pages or by changing the host.
 servers:
-  - url: https://{network}.g.alchemy.com/v2
-    variables:
-      network:
-        default: litecoin-mainnet
-        enum:
-          - litecoin-mainnet
-          - litecoin-testnet
+  - url: https://litecoin-mainnet.g.alchemy.com/v2
+    description: Litecoin mainnet
 paths:
   "/{apiKey}/api/v2/block-index/{block_height}":
     get: