entries for per network (#129)

Co-authored-by: macbook <lawaltoheeb36@gmail.com>

Author: codefather2026

.env.example

@@ -11,5 +11,6 @@ SOROBAN_NETWORK_PASSPHRASE="Test SDF Network ; September 2015"
 # Deployer secret key (private key) – placeholder only
 DEPLOYER_SECRET_KEY="SBXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
 
-# Contract ID placeholder
-CONTRACT_ID="CXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+# Contract ID placeholders by network
+CONTRACT_ID_PUBLIC="CXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+CONTRACT_ID_TESTNET="CXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"