ci: scope image prune to drsousan only, never touch other projects

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/ci-cd.yml

@@ -56,7 +56,7 @@ jobs:
         working-directory: DrSousan.Api
         run: dotnet build DrSousan.Api.csproj --no-restore -c Release
 
-  # ── CD: build image → push to Nexus → deploy (push to main only) ────────────
+  # ── CD: build image → deploy locally (push to main only) ───────────────────
   deploy:
     name: "Deploy · drsousan"
     runs-on: self-hosted
@@ -109,6 +109,12 @@ jobs:
         if: always()
         run: docker compose ps
 
-      - name: Prune old images
+      - name: Prune old drsousan images
         if: success()
-        run: docker image prune -f
+        # Only remove untagged (dangling) drsousan images — never touches other projects
+        run: |
+          docker images --format '{{.Repository}}:{{.Tag}} {{.ID}}' \
+            | grep '^mirror\.soroushasadi\.com/drsousan/' \
+            | grep '<none>' \
+            | awk '{print $2}' \
+            | xargs -r docker rmi || true