**build: update test results configuration and gitignore**

- Updated test results output path in `vitest.config.ts` to `./tests/results/test-results.json` for better organization.
- Modified `.gitignore` to include `/tests/results/` and its `.json` files to avoid committing test artifacts.

**Purpose**: Improves test results file structure and ensures consistent exclusion of test artifact files from version control.

.gitignore

@@ -47,6 +47,8 @@ Thumbs.db
 /test-worker.js
 /test-node24-worker.js
 /test-results.json
+/tests/results/
+/tests/results/*.json
 
 # Generated files
 /encoded-image.html

vitest.config.ts

@@ -44,7 +44,7 @@ export default defineConfig({
       [
         'json',
         {
-          outputFile: './test-results.json'
+          outputFile: './tests/results/test-results.json'
         }
       ]
     ],