feat: add knowledge version history (closes #75, closes #76)

- Added EntryVersion model with author relation
- Implemented automatic versioning on entry create/update
- Added API endpoints for version history:
  - GET /api/knowledge/entries/:slug/versions - list versions
  - GET /api/knowledge/entries/:slug/versions/:version - get specific
  - POST /api/knowledge/entries/:slug/restore/:version - restore version
- Created VersionHistory.tsx component with timeline view
- Added History tab to entry detail page
- Supports version viewing and restoring
- Includes comprehensive tests for version operations
- All TypeScript types are explicit and type-safe

packages/shared/src/types/database.types.ts

@@ -185,6 +185,32 @@ export interface KnowledgeEntryWithTags extends KnowledgeEntry {
   tags: KnowledgeTag[];
 }
 
+/**
+ * Knowledge entry version entity
+ */
+export interface KnowledgeEntryVersion {
+  readonly id: string;
+  entryId: string;
+  version: number;
+  title: string;
+  content: string;
+  summary: string | null;
+  readonly createdAt: Date;
+  createdBy: string;
+  changeNote: string | null;
+}
+
+/**
+ * Knowledge entry version with author information
+ */
+export interface KnowledgeEntryVersionWithAuthor extends KnowledgeEntryVersion {
+  author: {
+    id: string;
+    name: string;
+    email: string;
+  };
+}
+
 /**
  * Domain entity
  */