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

apps/api/src/knowledge/dto/index.ts

@@ -3,6 +3,7 @@ export { UpdateEntryDto } from "./update-entry.dto";
 export { EntryQueryDto } from "./entry-query.dto";
 export { CreateTagDto } from "./create-tag.dto";
 export { UpdateTagDto } from "./update-tag.dto";
+export { RestoreVersionDto } from "./restore-version.dto";
 export {
   SearchQueryDto,
   TagSearchDto,

apps/api/src/knowledge/dto/restore-version.dto.ts

@@ -0,0 +1,15 @@
+import {
+  IsString,
+  IsOptional,
+  MaxLength,
+} from "class-validator";
+
+/**
+ * DTO for restoring a previous version of a knowledge entry
+ */
+export class RestoreVersionDto {
+  @IsOptional()
+  @IsString({ message: "changeNote must be a string" })
+  @MaxLength(500, { message: "changeNote must not exceed 500 characters" })
+  changeNote?: string;
+}