ci: trigger workflow on PR with build-only validation

.github/workflows/admin-web-docker.yml

@@ -3,6 +3,10 @@ name: Admin Web Docker
 on:
   push:
     branches: [main]
+  pull_request:
+    paths:
+      - 'admin-web/**'
+      - '.github/workflows/admin-web-docker.yml'
   workflow_dispatch:
 
 concurrency:
@@ -13,15 +17,46 @@ env:
   NODE_VERSION: "22"
 
 jobs:
+  build-validation:
+    name: Docker Build Validation
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: Checkout
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3
+
+      - name: Install Docker CLI
+        run: sudo apt-get update -qq && sudo apt-get install -y -qq docker.io
+
+      - name: Build admin-web image (no push)
+        env:
+          NEXT_PUBLIC_SUPABASE_URL: ${{ vars.NEXT_PUBLIC_SUPABASE_URL }}
+          NEXT_PUBLIC_SUPABASE_ANON_KEY: ${{ vars.NEXT_PUBLIC_SUPABASE_ANON_KEY }}
+        run: |
+          set -e
+          docker build \
+            --file admin-web/Dockerfile \
+            --build-arg "NEXT_PUBLIC_SUPABASE_URL=${NEXT_PUBLIC_SUPABASE_URL}" \
+            --build-arg "NEXT_PUBLIC_SUPABASE_ANON_KEY=${NEXT_PUBLIC_SUPABASE_ANON_KEY}" \
+            --tag "tabatago-admin-web:pr-validation" \
+            admin-web
+
   semantic-release:
     name: Semantic Release
     runs-on: ubuntu-latest
     timeout-minutes: 10
     if: |
-      github.event_name == 'workflow_dispatch' ||
+      github.event_name != 'pull_request' &&
       (
-        !contains(github.event.head_commit.message, '[skip ci]') &&
-        !contains(github.event.head_commit.message, '[ci skip]')
+        github.event_name == 'workflow_dispatch' ||
+        (
+          !contains(github.event.head_commit.message, '[skip ci]') &&
+          !contains(github.event.head_commit.message, '[ci skip]')
+        )
       )
     outputs:
       released: ${{ steps.release.outputs.released }}