Add dev-ui compose override for zero-restart UI development

When developing the Angular console, use this override to bind-mount
the local dist directory directly into the gateway container:

  docker compose -f docker-compose.stella-ops.yml \
                 -f docker-compose.dev-ui.yml \
                 up -d router-gateway

After this, `ng build --configuration=development` writes directly to
where the gateway reads static files. No volume copy, no container
restart — just refresh the browser.

For watch mode: `ng build --configuration=development --watch`

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

devops/compose/docker-compose.dev-ui.yml

@@ -0,0 +1,13 @@
+# Development override: bind-mount local Angular build output directly
+# into the gateway container. Eliminates the need for volume copy + restart
+# after every `ng build`.
+#
+# Usage:
+#   docker compose -f docker-compose.stella-ops.yml -f docker-compose.dev-ui.yml up -d stellaops-router-gateway
+#
+# Then just run `ng build --configuration=development --watch` and refresh the browser.
+
+services:
+  router-gateway:
+    volumes:
+      - ../../src/Web/StellaOps.Web/dist/stellaops-web/browser:/app/wwwroot:ro