refactor: Improve Rhai test runner and vault module code

- Updated the Rhai test runner script to correctly find test files.
- Improved the structure and formatting of the `vault.rs` module.
- Minor code style improvements in multiple files.

run_rhai_tests.sh

@@ -24,7 +24,7 @@ log "${BLUE}      Running All Rhai Tests          ${NC}"
 log "${BLUE}=======================================${NC}"
 
 # Find all test runner scripts
-RUNNERS=$(find src/rhai_tests -name "run_all_tests.rhai")
+RUNNERS=$(find rhai_tests -name "run_all_tests.rhai")
 
 # Initialize counters
 TOTAL_MODULES=0