test: enhance security module with comprehensive token validation and rate limiting tests

- Expanded TokenManager test suite with advanced token encryption and decryption scenarios
- Added detailed rate limiting tests with IP-based tracking and window-based expiration
- Improved test coverage for token validation, tampering detection, and error handling
- Implemented mock configurations for faster test execution
- Enhanced security test scenarios with unique IP addresses and edge case handling

bunfig.toml

@@ -1,8 +1,22 @@
 [test]
 preload = ["./src/__tests__/setup.ts"]
 coverage = true
+coverageThreshold = {
+  statements = 80,
+  branches = 70,
+  functions = 80,
+  lines = 80
+}
 timeout = 30000
 testMatch = ["**/__tests__/**/*.test.ts"]
+testPathIgnorePatterns = ["/node_modules/", "/dist/"]
+collectCoverageFrom = [
+  "src/**/*.{ts,tsx}",
+  "!src/**/*.d.ts",
+  "!src/**/*.test.ts",
+  "!src/types/**/*",
+  "!src/mocks/**/*"
+]
 
 [build]
 target = "node"