Task Description
Scope: Replace all panic!() macros with a structured Result-based error system
Acceptance Criteria
Acceptance Criteria:
- Define custom error enums for each module (Bridge, Escrow, Rewards)
- Implement proper error propagation through all contract functions
- Add error codes and user-friendly error messages
- Update all tests to handle Result types instead of expecting panics
- Ensure gas-efficient error handling patterns