Add ECDSA signature verification and enhance ComboHandler functionality

- Integrated ECDSA for signature verification in ComboHandler.
- Updated event emissions to include additional parameters for better tracking.
- Improved gas tracking during execution of combo plans.
- Enhanced database interactions for storing and retrieving plans, including conflict resolution and status updates.
- Added new dependencies for security and database management in orchestrator.

orchestrator/src/middleware/index.ts

@@ -0,0 +1,8 @@
+export { apiLimiter, authLimiter, planCreationLimiter, executionLimiter } from "./rateLimit";
+export { securityHeaders, requestSizeLimits, requestId } from "./security";
+export { apiKeyAuth, optionalApiKeyAuth } from "./apiKeyAuth";
+export { validate, sanitizeInput } from "./validation";
+export { ipWhitelist, getClientIP } from "./ipWhitelist";
+export { auditLog } from "./auditLog";
+export { sessionManager } from "./session";
+