Replace the broken test suite with working GdUnit4 tests

The previous tests never compiled: they used GUT's assert functions,
Godot 3 APIs and reassigned autoload functions, so no test ran.

- 90 tests: unit tests for the playlist, songs, player scoring, time
  formatting, search and the server client, plus integration tests
  that run MainWindow and SyncWindow against a fake server
- Keybind tests check that Alt+<number> and Ctrl+Alt+<number> keep
  following the player rows while players are added and removed
- run_tests.sh finds Godot and runs the suite headless (~10 seconds)
- CI runs the tests before the build job in gitea-build.yaml; the
  separate test.yml used a GitHub action that does not exist
- GdUnit4 is committed instead of ignored, since the project enables
  it, and .gitea/ is no longer ignored
- Exported builds leave out tests/ and addons/gdUnit4/

.gitea/workflows/gitea-build.yaml

@@ -4,8 +4,10 @@
 #
 
 name: "Build"
-on: 
-  push: 
+on:
+  push:
+    branches: [main, develop]
+  pull_request:
     branches: [main, develop]
 
 env:
@@ -14,7 +16,24 @@ env:
   EXPORT_NAME: MusicPlayer
 
 jobs:
+  # Runs before build in the same workflow, so the two never race for the runner
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+      - name: Download Godot
+        run: |
+          curl -L -o godot.zip https://github.com/godotengine/godot-builds/releases/download/$GODOT_VERSION-stable/Godot_v$GODOT_VERSION-stable_linux.x86_64.zip
+          unzip godot.zip
+          mv Godot_v$GODOT_VERSION-stable_linux.x86_64 godot
+          chmod +x godot
+      - name: Run tests
+        run: GODOT=./godot ./run_tests.sh
+
   build:
+    needs: test
+    if: github.event_name == 'push'
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Repository

.gitea/workflows/test.yml

@@ -1,62 +0,0 @@
-name: Run Tests
-
-on:
-  push:
-    branches: [main, master]
-  pull_request:
-    branches: [main, master]
-
-jobs:
-  test:
-    name: Run GdUnit4 Tests
-    runs-on: ubuntu-latest
-    
-    steps:
-      - name: Checkout Repository
-        uses: https://github.com/actions/checkout@v4
-
-      - name: Setup Godot 4.7
-        uses: https://github.com/godotengine/godot-action@v1
-        with:
-          godot-version: 4.7
-
-      - name: Install GdUnit4
-        run: |
-          # GdUnit4 is already included in the repo at addons/gdUnit4
-          # Just verify it exists
-          if [ ! -d "addons/gdUnit4" ]; then
-            echo "GdUnit4 not found, downloading..."
-            wget https://github.com/godot-gdunit-labs/gdUnit4/releases/download/v6.2.1/gdUnit4-v6.2.1.zip
-            unzip -q gdUnit4-v6.2.1.zip
-            mv gdUnit4-v6.2.1/addons/gdUnit4 addons/gdUnit4
-            rm -rf gdUnit4-v6.2.1 gdUnit4-v6.2.1.zip
-          fi
-
-      - name: Run Tests (Headless)
-        run: |
-          # Run tests in headless mode
-          godot --path . -s addons/gdUnit4/test.gd --gdunit.cli
-        env:
-          GODOT_HEADLESS: 1
-
-      - name: Upload Test Results
-        if: always()
-        uses: https://github.com/actions/upload-artifact@v3
-        with:
-          name: test-results
-          path: |
-            test_results.xml
-            test_results.html
-          retention-days: 30
-
-      - name: Fail if Tests Failed
-        run: |
-          if [ ! -f "test_results.xml" ]; then
-            echo "Test results not found!"
-            exit 1
-          fi
-          # Check if there were any failures in the JUnit XML
-          if grep -q '<failure' test_results.xml; then
-            echo "Tests failed!"
-            exit 1
-          fi