* 🏗️ refactor: Improve spendTokens logic to handle zero completion tokens and enhance test coverage
* 🏗️ test: Add tests to ensure balance does not go below zero when spending tokens
* 🏗️ fix: Ensure proper continuation in AgentClient when handling errors
* fix: spend token race conditions
* 🏗️ test: Add test for handling multiple concurrent transactions with high balance
* fix: Handle Omni models prompt prefix handling for user messages with array content in OpenAIClient
* refactor: Update checkBalance import paths to use new balanceMethods module
* refactor: Update checkBalance imports and implement updateBalance function for atomic balance updates
* fix: import from replace method
* feat: Add createAutoRefillTransaction method to handle non-balance updating transactions
* refactor: Move auto-refill logic to balanceMethods and enhance checkBalance functionality
* feat: Implement logging for auto-refill transactions in balance checks
* refactor: Remove logRefill calls from multiple client and handler files
* refactor: Move balance checking and auto-refill logic to balanceMethods for improved structure
* refactor: Simplify balance check calls by removing unnecessary balanceRecord assignments
* fix: Prevent negative rawAmount in spendTokens when promptTokens is zero
* fix: Update balanceMethods to use Balance model for findOneAndUpdate
* chore: import order
* refactor: remove unused txMethods file to streamline codebase
* feat: enhance updateBalance and createAutoRefillTransaction methods to support additional parameters for improved balance management
