chore: migrate project to Bun testing framework and update configuration

- Replace Jest with Bun's native testing framework
- Update test configuration and utilities to support Bun test environment
- Add mock implementations for SSE and security testing
- Refactor test setup to use Bun's testing utilities
- Update package dependencies and scripts to align with Bun testing
- Enhance type definitions for Bun test mocking

bunfig.toml

@@ -0,0 +1,23 @@
+[test]
+preload = ["./src/__tests__/setup.ts"]
+coverage = true
+timeout = 30000
+testMatch = ["**/__tests__/**/*.test.ts"]
+
+[build]
+target = "node"
+outdir = "./dist"
+minify = true
+sourcemap = "external"
+
+[install]
+production = false
+frozen = true
+peer = false
+
+[install.cache]
+dir = ".bun"
+disable = false
+
+[debug]
+port = 9229