Merge pull request 'fix(ci): add concurrency guard + PR trigger + workflow_dispatch' (#2) from fix/ci-concurrency into main

.gitea/workflows/ci-cd.yaml

@@ -3,9 +3,20 @@ name: CI/CD Pipeline
 on:
   push:
     branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+# Serialise runs on the shared act_runner: prevents two simultaneous runs from
+# cancelling each other's in-progress steps (observed in older portfolio runs).
+# See python-project-template-internal/.gitea/workflows/ci.yaml for the same
+# pattern with full context (runs 794 and 799).
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: false
 
 jobs:
-  deploy:
+  build:
     name: Build & Deploy
     runs-on: ubuntu-latest
     steps:
@@ -15,4 +26,4 @@ jobs:
         run: |
           docker login gitlab.impresion3d.pro -u "${{ secrets.DOCKER_USERNAME }}" -p "${{ secrets.DOCKER_PASSWORD }}"
           docker build -t gitlab.impresion3d.pro/root/davidaragon-portfolio:latest .
-          docker push gitlab.impresion3d.pro/root/davidaragon-portfolio:latest
+          docker push gitlab.impresion3d.pro/root/davidaragon-portfolio:latest