Validation: #130 FeatureFlag implementation

validation-130-2026-06-07 Doc

validation pass landscaping-assistant
PR #144 merged. QA approved — 14 files, +617 lines, 32 new specs, 173 total passing.
Delivered: FeatureFlag model with cached lookups, feature_flags:sync rake task (stripe + client_requests), super admin UI at /platform/feature_flags, feature_enabled? helper, test support helpers.
Pending live validation: Requires Keycloak running — super admin UI gated by current_user_has_role?("super_admin"). Validate on deployed app after ArgoCD sync.
Three QA nits deferred: CSS magic number on code border-radius, with_feature_enabled ensure symmetry, with_keycloak duplication across spec files.