ci: migrate from ghcr.io to Gitea built-in registry

- Update REGISTRY env var: ghcr.io -> git.farh.net
- Replace Docker Hub + GHCR login with Gitea login step
- Remove credentials blocks from postgres and redis service definitions
- Update deploy-dev/deploy-uat kustomize image refs to use $REGISTRY var

Fixes QA FAIL from PR #23: missing Gitea login step.
Co-Authored-By: Paperclip <noreply@paperclip.ing>

.gitea/workflows/ci.yml

@@ -15,7 +15,7 @@ permissions:
   packages: write
 
 env:
-  REGISTRY: ghcr.io
+  REGISTRY: git.farh.net
   IMAGE_NAME: cartsnitch/api
 
 jobs:
@@ -51,9 +51,6 @@ jobs:
     services:
       postgres:
         image: postgres:15-alpine
-        credentials:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
         env:
           POSTGRES_USER: cartsnitch
           POSTGRES_PASSWORD: cartsnitch_test
@@ -67,9 +64,6 @@ jobs:
           --health-retries 5
       redis:
         image: redis:7-alpine
-        credentials:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
         ports:
           - 6379:6379
         options: >-
@@ -122,19 +116,8 @@ jobs:
           echo "version=$VERSION" >> "$GITHUB_OUTPUT"
           echo "CalVer tag: $VERSION"
 
-      - name: Log in to Docker Hub
-        uses: docker/login-action@v3
-        with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-
-      - name: Log in to GHCR
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
-        uses: docker/login-action@v3
-        with:
-          registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Log in to Gitea Container Registry
+        run: echo "${{ github.token }}" | docker login git.farh.net -u ${{ github.actor }} --password-stdin
 
       - name: Extract metadata
         id: meta
@@ -171,7 +154,7 @@ jobs:
           only-fixed: "true"
           output-format: sarif
 
-      
+
 
       - name: Push Docker image
         if: github.event_name == 'push'
@@ -224,7 +207,7 @@ jobs:
         if: needs.build-and-push.result == 'success'
         run: |
           cd infra/apps/overlays/dev
-          kustomize edit set image ghcr.io/cartsnitch/api:${{ steps.api_tag.outputs.tag }}
+          kustomize edit set image ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.api_tag.outputs.tag }}
 
       - name: Commit and push to infra
         run: |
@@ -268,7 +251,7 @@ jobs:
         if: needs.build-and-push.result == 'success'
         run: |
           cd infra/apps/overlays/uat
-          kustomize edit set image ghcr.io/cartsnitch/api:${{ steps.api_tag.outputs.tag }}
+          kustomize edit set image ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.api_tag.outputs.tag }}
 
       - name: Commit and push to infra
         run: |