Migrate build pipeline from GitLab to GitHub Actions with manual dispatch triggers (#18)

* Initial plan

* Migrate build pipeline from GitLab to GitHub with dispatch triggers

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Create new GitLab migration build workflow without modifying existing files

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Remove test jobs from GitLab migration build workflow as requested

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Add helm chart build job to GitLab migration workflow

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Change default helm chart path to deploy/chart

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Remove helm chart build job and related input parameters as requested

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

Author: Copilot

.github/workflows/gitlab-migration-build.yaml

@@ -0,0 +1,98 @@
+name: GitLab Migration Build Pipeline
+
+# Migrated from GitLab CI - using dispatch trigger only as requested
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Version to use for build (defaults to commit SHA)'
+        required: false
+        type: string
+        default: ''
+
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  # Build frontend container - migrated from build-container-ui
+  build-container-ui:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Set version
+        id: version
+        run: |
+          if [ -n "${{ inputs.version }}" ]; then
+            echo "VERSION=${{ inputs.version }}" >> $GITHUB_ENV
+          elif [ "${{ github.ref_type }}" == "tag" ]; then
+            echo "VERSION=${{ github.ref_name }}" >> $GITHUB_ENV
+          else
+            echo "VERSION=${{ github.sha }}" >> $GITHUB_ENV
+          fi
+          echo "SHORT_SHA=${GITHUB_SHA:0:8}" >> $GITHUB_ENV
+      
+      - uses: docker/setup-buildx-action@v3
+      
+      - name: Build frontend container
+        uses: docker/build-push-action@v6
+        with:
+          context: frontend/
+          file: frontend/Dockerfile
+          build-args: |
+            VERSION=${{ env.VERSION }}
+            CI=true
+          tags: rag-eval-ui:${{ env.SHORT_SHA }}
+          outputs: type=docker,dest=/tmp/frontend.tar
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+      
+      - name: Upload frontend artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: frontend.tar
+          path: /tmp/frontend.tar
+          retention-days: 2
+
+  # Build backend container - migrated from build-container-backend  
+  build-container-backend:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Set version
+        id: version
+        run: |
+          if [ -n "${{ inputs.version }}" ]; then
+            echo "VERSION=${{ inputs.version }}" >> $GITHUB_ENV
+          elif [ "${{ github.ref_type }}" == "tag" ]; then
+            echo "VERSION=${{ github.ref_name }}" >> $GITHUB_ENV
+          else
+            echo "VERSION=${{ github.sha }}" >> $GITHUB_ENV
+          fi
+          echo "SHORT_SHA=${GITHUB_SHA:0:8}" >> $GITHUB_ENV
+      
+      - uses: docker/setup-buildx-action@v3
+      
+      - name: Build backend container
+        uses: docker/build-push-action@v6
+        with:
+          context: backend/
+          file: backend/Dockerfile
+          build-args: |
+            VERSION=${{ env.VERSION }}
+            CI=true
+          tags: llm-eval-backend:${{ env.SHORT_SHA }}
+          outputs: type=docker,dest=/tmp/backend.tar
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+      
+      - name: Upload backend artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: backend.tar
+          path: /tmp/backend.tar
+          retention-days: 2
+