feat(P5): IHF Phase 5 complete — agent-assisted distillation

Adds bounded AI support to the IHF governance loop. All AI outputs are
attributed (model_ref), reviewable (AgentReviewRecord), and reversible.
No autonomous decisions; no silent requirement promotion.

- T01: Schema — agent_proposals, agent_review_records,
  confidence_annotations (migration 1743379200)
- T02: AgentProposalsController (index/show/accept/reject, idempotent
  review guard), global nav "Agent" link
- T03: SummarizeClusterAction — Claude API cluster summary on widget show
- T04: DraftRequirementAction — AI requirement draft; acceptance creates
  RequirementCandidate (human-gated)
- T05: DetectDuplicatesAction — duplicate_flag proposal on candidate show
- T06: DetectPolicySensitivityAction — policy_flag with
  ConfidenceAnnotations per concern scope
- T07: ProposeImplementationAction — impl_proposal from decision show
- T08: AgentAuditDashboardAction — autoRefresh; KPI row, unreviewed queue,
  recent proposals, attribution log matrix
- T09: integration tests, SCOPE.md updated, phase5-summary.md, flake.nix
  adds http-conduit/aeson/string-conversions

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

Web/View/Widgets/Show.hs

@@ -82,8 +82,22 @@ instance View ShowView where
             <section>
                 <div class="flex items-center justify-between mb-3">
                     <h2 class="text-lg font-medium">Annotations</h2>
-                    <a href={NewAnnotationAction { widgetId = widget.id }}
-                       class="text-sm text-indigo-600 hover:text-indigo-800">+ Add</a>
+                    <div class="flex items-center gap-2">
+                        {if length annotations >= 3 then [hsx|
+                            <form method="POST" action={DraftRequirementAction { widgetId = widget.id }} class="inline">
+                                <button type="submit" class="text-xs border border-indigo-300 text-indigo-700 px-2 py-1 rounded hover:bg-indigo-50">
+                                    Draft Requirement
+                                </button>
+                            </form>
+                        |] else mempty}
+                        <form method="POST" action={SummarizeClusterAction { widgetId = widget.id }} class="inline">
+                            <button type="submit" class="text-xs border border-blue-300 text-blue-700 px-2 py-1 rounded hover:bg-blue-50">
+                                Summarize Feedback
+                            </button>
+                        </form>
+                        <a href={NewAnnotationAction { widgetId = widget.id }}
+                           class="text-sm text-indigo-600 hover:text-indigo-800">+ Add</a>
+                    </div>
                 </div>
                 <div class="space-y-2">
                     {forEach rootAnnotations (renderAnnotation childrenOf)}