test(cortex-plugins): add lifecycle tests and fix clippy warning

- Add comprehensive lifecycle tests covering plugin discover → load → init → hook → shutdown flow
- Add tests for PluginManager creation, discovery, loading, and lifecycle management
- Add tests for WasmRuntime and WasmPlugin
- Add tests for PluginConfig settings
- Add tests for HookRegistry and HookDispatcher
- Add tests for EventBus and event subscription
- Add tests for PluginCommand and command registry
- Fix clippy warning: replace vec![] with array for constant case list

Author: echobt

src/cortex-plugins/tests/edge_case_tests.rs

@@ -124,7 +124,7 @@ version = "{}"
 
     #[test]
     fn test_manifest_invalid_toml_syntax() {
-        let invalid_toml_cases = vec![
+        let invalid_toml_cases = [
             // Missing closing bracket
             "[plugin\nid = \"test\"",
             // Invalid key syntax