🎉 MAJOR: Shared libraries architecture complete with Vault integration

COMPLETED:
✅ Created 3 shared libraries: common, config (foxhunt-config), storage
✅ Config library: PostgreSQL hot-reload, Vault integration, unified ConfigManager
✅ Storage library: S3 with Vault credentials, model checkpoints, zero hardcoded keys
✅ Common library: Shared types, database connections, error handling
✅ Fixed TLI protobuf compilation issues (duplicate health_check, Aad types)
✅ Trading Service migrated to use centralized config

SECURITY IMPROVEMENTS:
🔒 ALL AWS credentials now from Vault (no environment variables)
🔒 Circuit breaker patterns for external services
🔒 Secure error messages that don't leak credentials
🔒 Automatic credential refresh with 5-minute TTL

ARCHITECTURE:
- Single source of truth for configuration
- Zero code duplication for common functionality
- Hot-reload capability via PostgreSQL NOTIFY/LISTEN
- Multi-tier storage with compression and lifecycle management
- Type-safe configuration with comprehensive error handling

Next: Complete service migrations to use shared libraries

common/Cargo.toml

@@ -34,7 +34,7 @@ chrono = { workspace = true, features = ["serde"] }
 rust_decimal = { workspace = true, features = ["serde", "macros"] }
 
 # Database dependencies
-sqlx = { workspace = true, features = ["runtime-tokio-rustls", "postgres", "chrono", "uuid"] }
+sqlx = { workspace = true, features = ["runtime-tokio-rustls", "postgres", "chrono", "uuid"], optional = true }
 redis.workspace = true
 
 # Logging and tracing