[tests] suppress debug logs in CI environment

Set LOG_LEVEL=ERROR in vitest-setup.js when running in CI to reduce
verbose console output while keeping full logging for local development.

Author: KristjanESPERANTO

CHANGELOG.md

@@ -22,7 +22,7 @@ planned for 2026-01-01
 - [check_config] refactor: improve error handling (#3927)
 - [calendar] test: remove "Recurring event per timezone" test (#3929)
 - [calendar] chore: remove `requiresVersion: "2.1.0"` (#3932)
-- [tests] migrate from `jest` to `vitest` (#3940)
+- [tests] migrate from `jest` to `vitest` (#3940, #3941)
 
 ### Fixed
 

tests/utils/vitest-setup.js

@@ -1,11 +1,16 @@
 /**
- * Vitest setup file for module aliasing
+ * Vitest setup file for module aliasing and CI logging
  * This allows require("logger") to work in unit tests
  */
 
 const Module = require("node:module");
 const path = require("node:path");
 
+// Suppress debug/info logs in CI to keep output clean
+if (process.env.CI === "true" && !process.env.LOG_LEVEL) {
+	process.env.LOG_LEVEL = "ERROR";
+}
+
 // Store the original require
 const originalRequire = Module.prototype.require;