tower 0.61.2 / tower-ui 0.61.7 — fixes from end-to-end smoke

3 bugs caught while smoke-testing the multi-tenant signup → first
deploy flow:

1. /api/me returned capabilities: null when scope.role was nil
   (a tenant member viewing the platform tenant context). Frontend's
   useAuth.can() does for-of on the array → TypeError. Fix: backend
   returns []string{} not nil; frontend defends against null.

2. WelcomeView slug input pattern '[a-z][a-z0-9-]{2,39}' is rejected
   by Firefox's HTML5 form validation under the v-flag (treats trailing
   '-' as a class-range start). Move hyphen to start of the class.

3. Domain & DNS Save button is genuinely separate from the Cloudflare
   token Save (by design — token rotates independently). Documenting
   here so the next person doesn't think they saved when they didn't.

values.yaml

@@ -9,7 +9,7 @@ backend:
     # so every cluster that runs Tower needs the same imagePullSecret
     # provisioned out-of-band (until cluster-platform-v3 owns it).
     repository: registry.odoosky.cloud/odoosky/docker-mirror/tower
-    tag: "0.61.1"
+    tag: "0.61.2"
     pullPolicy: IfNotPresent
   imagePullSecrets:
     - name: docker-mirror-pull
@@ -29,7 +29,7 @@ frontend:
   enabled: true
   image:
     repository: registry.odoosky.cloud/odoosky/docker-mirror/tower-ui
-    tag: "0.61.6"
+    tag: "0.61.7"
     pullPolicy: IfNotPresent
   imagePullSecrets:
     - name: docker-mirror-pull