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/knowledge.controller.ts

@@ -8,9 +8,11 @@ import {
   Param,
   Query,
   UseGuards,
+  ParseIntPipe,
+  DefaultValuePipe,
 } from "@nestjs/common";
 import { KnowledgeService } from "./knowledge.service";
-import { CreateEntryDto, UpdateEntryDto, EntryQueryDto } from "./dto";
+import { CreateEntryDto, UpdateEntryDto, EntryQueryDto, RestoreVersionDto } from "./dto";
 import { AuthGuard } from "../auth/guards/auth.guard";
 import { WorkspaceGuard, PermissionGuard } from "../common/guards";
 import { Workspace, Permission, RequirePermission } from "../common/decorators";
@@ -132,4 +134,58 @@ export class KnowledgeController {
       count: backlinks.length,
     };
   }
+
+  /**
+   * GET /api/knowledge/entries/:slug/versions
+   * List all versions for an entry with pagination
+   * Requires: Any workspace member
+   */
+  @Get(":slug/versions")
+  @RequirePermission(Permission.WORKSPACE_ANY)
+  async getVersions(
+    @Workspace() workspaceId: string,
+    @Param("slug") slug: string,
+    @Query("page", new DefaultValuePipe(1), ParseIntPipe) page: number,
+    @Query("limit", new DefaultValuePipe(20), ParseIntPipe) limit: number
+  ) {
+    return this.knowledgeService.findVersions(workspaceId, slug, page, limit);
+  }
+
+  /**
+   * GET /api/knowledge/entries/:slug/versions/:version
+   * Get a specific version of an entry
+   * Requires: Any workspace member
+   */
+  @Get(":slug/versions/:version")
+  @RequirePermission(Permission.WORKSPACE_ANY)
+  async getVersion(
+    @Workspace() workspaceId: string,
+    @Param("slug") slug: string,
+    @Param("version", ParseIntPipe) version: number
+  ) {
+    return this.knowledgeService.findVersion(workspaceId, slug, version);
+  }
+
+  /**
+   * POST /api/knowledge/entries/:slug/restore/:version
+   * Restore a previous version of an entry
+   * Requires: MEMBER role or higher
+   */
+  @Post(":slug/restore/:version")
+  @RequirePermission(Permission.WORKSPACE_MEMBER)
+  async restoreVersion(
+    @Workspace() workspaceId: string,
+    @Param("slug") slug: string,
+    @Param("version", ParseIntPipe) version: number,
+    @CurrentUser() user: any,
+    @Body() restoreDto: RestoreVersionDto
+  ) {
+    return this.knowledgeService.restoreVersion(
+      workspaceId,
+      slug,
+      version,
+      user.id,
+      restoreDto.changeNote
+    );
+  }
 }