feat(core): Add backend services, scripts, and initial test structure

backend/.env.example

@@ -0,0 +1,9 @@
+# PezkuwiChain WebSocket Endpoint
+WS_ENDPOINT=wss://ws.pezkuwichain.io
+
+# Sudo account seed phrase for auto-approval
+# This account will sign approve_kyc transactions when threshold is reached
+SUDO_SEED=your_seed_phrase_here
+
+# Server port
+PORT=3001