chore: tophat builds for PR scope

.github/workflows/tophat-build-request.yml

@@ -0,0 +1,67 @@
+---
+  name: Tophat Build Request
+
+  # Triggers tophat build in oasis-frontend for each PR
+  # This allows PRs to be tested on the staging environment
+
+  on:
+    pull_request:
+      types: [opened, synchronize]
+      paths:
+       - '**'
+
+  jobs:
+    notify:
+      name: 'Trigger Tophat Build'
+      runs-on: ubuntu-latest
+      permissions:
+          pull-requests: write
+      steps:
+        - name: Get PR Info
+          id: pr_info
+          run: |
+            echo "branch=${{ github.head_ref }}" >> $GITHUB_OUTPUT
+            echo "pr_number=${{ github.event.pull_request.number }}" >> $GITHUB_OUTPUT
+            echo "sha=$(echo '${{ github.event.pull_request.head.sha }}' | cut -c1-7)" >> $GITHUB_OUTPUT
+
+        - name: Trigger oasis-frontend Tophat Build
+          env:
+            BUILDKITE_BEARER: ${{ secrets.BUILDKITE_BEARER }}
+            BUILDKITE_PIPELINE: ${{ secrets.BUILDKITE_PIPELINE }}
+          run: |
+            echo "🚀 Triggering tophat build for branch: ${{ steps.pr_info.outputs.branch }}"
+            echo "PR: #${{ steps.pr_info.outputs.pr_number }}"
+
+            curl -s -o /dev/null -w "%{http_code}" \
+            -H "Authorization: Bearer $BUILDKITE_BEARER" \
+            -X POST "https://api.buildkite.com/v2/organizations/$BUILDKITE_PIPELINE/builds" \
+            -H "Content-Type: application/json" \
+            -d '{
+              "commit": "HEAD",
+              "code": "curl",
+              "branch": "main",
+              "message": "Tophat build for PR #${{ steps.pr_info.outputs.pr_number }}",
+              "author": {
+                "name": "Tangle-UI Workflow",
+                "email": "ci@tangleml.com"
+              },
+              "env": {
+                "TOPHAT_BRANCH": "${{ steps.pr_info.outputs.branch }}"
+              }
+            }' || echo "Note: Buildkite trigger may need configuration"
+
+            echo "✅ Tophat build triggered"
+
+        - name: Comment on PR
+          uses: mshick/add-pr-comment@v2
+          env:
+              GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          with:
+              message: |
+                  ### :tophat: To tophat this PR:
+
+                  You can add the following URL parameter to your browser to tophat this PR:
+
+                      `?tophat_location=${{ steps.pr_info.outputs.branch }}/${{ steps.pr_info.outputs.sha }}`
+
+                  ---