feat(T02-T11): IHF Phase 1 schema, controllers, views, and helpers

- Schema: hubs, widgets, widget_versions, interaction_events (append-only
  trigger), annotations, users — single migration file
- Web layer: Types, Routes, FrontController with auth + AutoRefresh layout
- Controllers: Hubs (CRUD), Widgets (CRUD + versioning), InteractionEvents
  (JSON capture, canonical event_type validation), Annotations (threaded,
  append-only)
- Sessions controller for IHP auth
- Views: Hubs (index/show/new/edit), Widgets (index/show/new/edit),
  Annotations (index/new), Sessions (login)
- widgetEnvelope helper with full data-* governance attributes
- Integration tests: Hub CRUD, Widget versioning, event capture, append-only
  guard, annotation threading, validation

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

Application/Helper/View.hs

@@ -1,5 +1,44 @@
 module Application.Helper.View where
 
 import IHP.ViewPrelude
+import Generated.Types
+import Web.Types
 
--- Here you can add functions which are available in all your views
+-- | Widget Envelope — wraps any widget's rendered content with IHF governance metadata.
+--
+-- Every interactive element that is part of the governed widget registry should
+-- be wrapped with this helper. It injects the stable data-* attributes that the
+-- client-side event capture script reads to identify the widget without coupling
+-- to implementation details.
+--
+-- Usage:
+--
+-- @
+-- widgetEnvelope widget [hsx|
+--     <button>Click me</button>
+-- |]
+-- @
+--
+-- See docs/widget-envelope-convention.md for the full convention.
+widgetEnvelope :: Widget -> Html -> Html
+widgetEnvelope widget inner = [hsx|
+    <div
+        class="ihf-widget"
+        data-widget-id={tshow widget.id}
+        data-widget-type={widget.widgetType}
+        data-hub-id={tshow widget.hubId}
+        data-capability-ref={fromMaybe "" widget.capabilityRef}
+        data-view-context={fromMaybe "" widget.viewContext}
+        data-policy-scope={widget.policyScope}
+        data-widget-version={tshow widget.version}
+    >
+        {inner}
+        <div class="ihf-widget-controls mt-2">
+            <a href={WidgetAnnotationsAction { widgetId = widget.id }}
+               class="ihf-annotate-btn text-xs text-gray-400 hover:text-indigo-600 border border-gray-200
+                      rounded px-2 py-0.5 hover:border-indigo-300">
+                Annotate
+            </a>
+        </div>
+    </div>
+|]