fix(WP-0017/E3): Layer 3 error fixes — controllers and views

Fix compilation errors across 6 controllers and 29 views: import cleanup,
ResponseException pattern for API auth, type fixes, unused import removal.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Web/View/Hubs/AntifragilityDashboard.hs

@@ -93,7 +93,7 @@ instance View AntifragilityDashboardView where
             {renderRecurrenceSection recurrenceLeaderboard widgets}
         </div>
     |]
-  where
+      where
     deployedIds    = map (.id) allDeployments
     openGaps       = filter (\d -> any (\r -> r.decisionId == d.id) allImplRefs
                                 && not (any (\dp -> dp.decisionId == d.id) allDeployments))