ci: add workflow_dispatch with workspace ref input

.github/workflows/build-healthchat.yaml

@@ -5,6 +5,13 @@ on:
     push:
         branches:
             - release/healthchat
+    workflow_dispatch:
+        inputs:
+            healthchat_workspace_ref:
+                description: "healthchat-workspace git ref (tag, branch, or SHA). Leave empty for default branch."
+                required: false
+                default: ""
+                type: string
 
 jobs:
     build-healthchat-app:
@@ -31,6 +38,7 @@ jobs:
                   repository: Novaloop-AG/healthchat-workspace
                   path: healthchat-workspace
                   token: ${{ secrets.HEALTHCHAT_WORKSPACE_TOKEN }}
+                  ref: ${{ github.event.inputs.healthchat_workspace_ref || '' }}
             - name: Setup Node.js
               uses: actions/setup-node@v4
               with: