feat: add RAG corpus versioning and source policy backend

Part 1 — RAG Corpus Versioning:
- New DB table compliance_corpus_versions (migration 017)
- Go CorpusVersionStore with CRUD operations
- Assessment struct extended with corpus_version_id
- API endpoints: GET /rag/corpus-status, /rag/corpus-versions/:collection
- RAG routes (search, regulations) now registered in main.go
- Ingestion script registers corpus versions after each run
- Frontend staleness badge in SDK sidebar

Part 3 — Source Policy Backend:
- New FastAPI router with CRUD for allowed sources, PII rules,
  operations matrix, audit trail, stats, and compliance report
- SQLAlchemy models for all source policy tables (migration 001)
- Frontend API base corrected from edu-search:8088/8089 to
  backend-compliance:8002/api

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

admin-compliance/lib/sdk/context.tsx

@@ -102,6 +102,9 @@ const initialState: SDKState = {
   // IACE (Industrial AI Compliance Engine)
   iaceProjects: [],
 
+  // RAG Corpus Versioning
+  ragCorpusStatus: null,
+
   // Security
   sbom: null,
   securityIssues: [],

admin-compliance/lib/sdk/types.ts

@@ -975,6 +975,22 @@ export interface SBOMDependency {
   to: string
 }
 
+// RAG Corpus Versioning
+export interface RAGCorpusCollectionStatus {
+  id: string
+  current_version: string
+  documents_count: number
+  chunks_count: number
+  regulations: string[]
+  last_updated: string
+  digest: string
+}
+
+export interface RAGCorpusStatus {
+  collections: Record<string, RAGCorpusCollectionStatus>
+  fetchedAt: string
+}
+
 export interface SBOM {
   format: 'CycloneDX' | 'SPDX'
   version: string
@@ -1504,6 +1520,9 @@ export interface SDKState {
   // IACE (Industrial AI Compliance Engine)
   iaceProjects: IACEProjectSummary[]
 
+  // RAG Corpus Versioning
+  ragCorpusStatus: RAGCorpusStatus | null
+
   // Security
   sbom: SBOM | null
   securityIssues: SecurityIssue[]