Refactor Dockerfile and CI workflow for improved dependency management and cleanup

- Updated Dockerfile to optimize layer caching by copying requirements.txt before application code.
- Added caching for pip packages in CI workflow to speed up dependency installation.
- Implemented cleanup of dangling Docker images post-deployment.

.gitea/workflows/ci.yml

@@ -20,6 +20,12 @@ jobs:
         with:
           python-version: '3.11'
 
+      - name: Cache pip packages
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('api/requirements.txt') }}
+
       - name: Установка зависимостей
         run: |
           cd api
@@ -112,6 +118,7 @@ jobs:
           while [ $elapsed -lt $timeout ]; do
             if docker logs fastapi-container 2>&1 | grep -q "Application startup complete"; then
               echo "Application startup detected in logs"
+              echo "Deployment successful!"
               exit 0
             fi
             echo "Waiting for startup log... ($elapsed/$timeout sec)"
@@ -120,8 +127,14 @@ jobs:
           done
           echo "Timeout: Application startup not detected in logs"
           docker logs fastapi-container
-          echo "Deployment successful!"
           exit 1
+      
+      - name: Clean up dangling images
+        run: |
+          echo "Removing old dangling images..."
+          docker image prune -f
+          echo "Current images after cleanup:"
+          docker images
 
   # Явный статус для PR
   pr-status: