fix: adapt to pnpm monorepo after rebase onto master

Post-rebase fixups for the v1.12.7 -> v1.12.20 jump (yarn single-package
-> pnpm monorepo):

- UserSettingsDialog: TranslationKey is now a global ambient type (drop
  the import); remove imports left unused by the disabled Account/Security
  tabs; cast the module tab icon to the tightened Tab icon type.
- SdkConfig: point the default branding auth_header_logo_url at the PNG
  logo (the SVG was removed by HealthChat branding), fixing a broken
  default asset reference.
- build-healthchat.yaml: build apps/web/Dockerfile (monorepo location).

.github/workflows/build-healthchat.yaml

@@ -168,7 +168,7 @@ jobs:
               uses: docker/build-push-action@v6
               with:
                   context: .
-                  file: ./Dockerfile
+                  file: ./apps/web/Dockerfile
                   push: ${{ env.DOCKER_PUSH }}
                   tags: ${{ steps.metadata.outputs.tags }}
                   labels: ${{ steps.metadata.outputs.labels }}