refactor(coordinator): standardize database path to follow blockchain-node pattern

- Change coordinator database from /opt/data/coordinator.db to ./data/coordinator.db
- Update config.py to use relative path consistent with blockchain-node
- Update deployment scripts to use /opt/coordinator-api/data/coordinator.db
- Add data directory creation in init_db() for consistency
- Update .env.example files to reflect new standard
- Maintain backward compatibility for production deployment

gpu_acceleration/research/gpu_zk_research/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "gpu_zk_research"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+halo2 = { version = "0.1.0-beta.2" }
+halo2_proofs = { version = "0.1.0-beta.2" }
+halo2_gadgets = { version = "0.1.0-beta.2" }
+pasta_curves = "0.5"
+rand = "0.8"
+anyhow = "1.0"