feat(ci): add CI pipeline with linting, building, and testing jobs

.github/workflows/unit-tests.yml

@@ -0,0 +1,63 @@
+name: Unit Tests
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main, develop ]
+
+jobs:
+  unit-tests:
+    name: Run Unit Tests
+    runs-on: ubuntu-latest
+    
+    strategy:
+      matrix:
+        go-version: ['1.23.x']
+    
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: ${{ matrix.go-version }}
+        
+    - name: Cache Go modules
+      uses: actions/cache@v4
+      with:
+        path: |
+          ~/.cache/go-build
+          ~/go/pkg/mod
+        key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+        restore-keys: |
+          ${{ runner.os }}-go-
+          
+    - name: Download dependencies
+      run: go mod download
+      
+    - name: Verify dependencies
+      run: go mod verify
+      
+    - name: Run unit tests
+      run: |
+        # Run unit tests with coverage, excluding integration tests
+        go test -v -race -coverprofile=coverage.out -covermode=atomic ./internal/...
+        
+    - name: Generate coverage report
+      run: go tool cover -html=coverage.out -o coverage.html
+      
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v4
+      with:
+        file: ./coverage.out
+        flags: unittests
+        name: codecov-umbrella
+        fail_ci_if_error: false
+        
+    - name: Upload coverage artifact
+      uses: actions/upload-artifact@v4
+      with:
+        name: coverage-report
+        path: coverage.html