fixed build process and added project configuration files from idea

.gitea/workflows/build.yml

@@ -12,8 +12,43 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+
     - name: Set up JDK 20
       uses: actions/setup-java@v5
       with:
         java-version: '20'
         distribution: 'temurin'
+
+    - name: Create output directories
+      run: |
+        mkdir -p out/production/Calc
+        mkdir -p dist
+
+    - name: Compile Java files
+      run: |
+        javac -encoding UTF-8 -cp "lib/flatlaf-3.7.jar" -d out/production/Calc \
+          $(find src/main/java -name "*.java")
+
+    - name: Copy resources
+      run: |
+        if [ -d "src/main/resources" ]; then
+          cp -r src/main/resources/* out/production/Calc/ 2>/dev/null || true
+        fi
+
+    - name: Create manifest
+      run: |
+        echo "Manifest-Version: 1.0" > manifest.txt
+        echo "Main-Class: dev.sillyangel.calc.Calculator" >> manifest.txt
+        echo "Class-Path: lib/flatlaf-3.7.jar" >> manifest.txt
+
+    - name: Create JAR
+      run: |
+        cd out/production/Calc
+        jar cfm ../../../dist/CalcShortforCalculator.jar ../../../manifest.txt .
+        cd ../../..
+
+    - name: Upload JAR artifact
+      uses: actions/upload-artifact@v4
+      with:
+        name: CalcShortforCalculator
+        path: dist/CalcShortforCalculator.jar