feat(sdk): Add Drafting Engine with 4-mode agent system (Explain/Ask/Draft/Validate)

Extends the Compliance Advisor from a Q&A chatbot into a full drafting engine
that can generate, validate, and refine compliance documents within Scope Engine
constraints. Includes intent classifier, state projector, constraint enforcer,
SOUL templates, Go backend endpoints, and React UI components.

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

admin-v2/components/sdk/ComplianceAdvisorWidget.tsx

@@ -15,6 +15,7 @@ interface Message {
 
 interface ComplianceAdvisorWidgetProps {
   currentStep?: string
+  enableDraftingEngine?: boolean
 }
 
 // =============================================================================
@@ -58,7 +59,13 @@ const EXAMPLE_QUESTIONS: Record<string, string[]> = {
 // COMPONENT
 // =============================================================================
 
-export function ComplianceAdvisorWidget({ currentStep = 'default' }: ComplianceAdvisorWidgetProps) {
+export function ComplianceAdvisorWidget({ currentStep = 'default', enableDraftingEngine = false }: ComplianceAdvisorWidgetProps) {
+  // Feature-flag: If Drafting Engine enabled, render DraftingEngineWidget instead
+  if (enableDraftingEngine) {
+    const { DraftingEngineWidget } = require('./DraftingEngineWidget')
+    return <DraftingEngineWidget currentStep={currentStep} enableDraftingEngine />
+  }
+
   const [isOpen, setIsOpen] = useState(false)
   const [isExpanded, setIsExpanded] = useState(false)
   const [messages, setMessages] = useState<Message[]>([])