Redirect vlogs root to the VictoriaLogs UI (#504)

Visiting https://vlogs.unkin.net/ currently lands on the bare VictoriaLogs index page with relative links, not the query UI.

- Add an Exact `/` rule to the `vlogs` HTTPRoute that 302s to `/select/vmui/`
- Keep the PathPrefix `/` catch-all pointed at `vlogs-oauth2:80`, so auth is unchanged

Reviewed-on: #504
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

apps/base/logging/vlogs/httproute.yaml

@@ -37,6 +37,18 @@ spec:
       name: vlogs-external
       sectionName: https
   rules:
+    # Exact / outranks the PathPrefix catch-all; target needs the trailing slash
+    - filters:
+        - type: RequestRedirect
+          requestRedirect:
+            path:
+              type: ReplaceFullPath
+              replaceFullPath: /select/vmui/
+            statusCode: 302
+      matches:
+        - path:
+            type: Exact
+            value: /
     - backendRefs:
         - group: ""
           kind: Service