feat(#82): implement Personality Module

- Add Personality model to Prisma schema with FormalityLevel enum
- Create migration and seed with 6 default personalities
- Implement CRUD API with TDD approach (97.67% coverage)
  * PersonalitiesService: findAll, findOne, findDefault, create, update, remove
  * PersonalitiesController: REST endpoints with auth guards
  * Comprehensive test coverage (21 passing tests)
- Add Personality types to shared package
- Create frontend components:
  * PersonalitySelector: dropdown for choosing personality
  * PersonalityPreview: preview personality style and system prompt
  * PersonalityForm: create/edit personalities with validation
  * Settings page: manage personalities with CRUD operations
- Integrate with Ollama API:
  * Support personalityId in chat endpoint
  * Auto-inject system prompt from personality
  * Fall back to default personality if not specified
- API client for frontend personality management

All tests passing with 97.67% backend coverage (exceeds 85% requirement)

apps/api/src/personalities/personalities.controller.ts

@@ -0,0 +1,77 @@
+import {
+  Controller,
+  Get,
+  Post,
+  Put,
+  Delete,
+  Body,
+  Param,
+  Query,
+  UseGuards,
+  Req,
+} from "@nestjs/common";
+import { AuthGuard } from "../auth/guards/auth.guard";
+import { PersonalitiesService } from "./personalities.service";
+import { CreatePersonalityDto, UpdatePersonalityDto } from "./dto";
+import { Personality } from "./entities/personality.entity";
+
+@Controller("personalities")
+@UseGuards(AuthGuard)
+export class PersonalitiesController {
+  constructor(private readonly personalitiesService: PersonalitiesService) {}
+
+  /**
+   * Get all personalities for the current workspace
+   */
+  @Get()
+  async findAll(
+    @Req() req: any,
+    @Query("isActive") isActive: boolean = true,
+  ): Promise<Personality[]> {
+    return this.personalitiesService.findAll(req.workspaceId, isActive);
+  }
+
+  /**
+   * Get the default personality for the current workspace
+   */
+  @Get("default")
+  async findDefault(@Req() req: any): Promise<Personality> {
+    return this.personalitiesService.findDefault(req.workspaceId);
+  }
+
+  /**
+   * Get a specific personality by ID
+   */
+  @Get(":id")
+  async findOne(@Req() req: any, @Param("id") id: string): Promise<Personality> {
+    return this.personalitiesService.findOne(req.workspaceId, id);
+  }
+
+  /**
+   * Create a new personality
+   */
+  @Post()
+  async create(@Req() req: any, @Body() dto: CreatePersonalityDto): Promise<Personality> {
+    return this.personalitiesService.create(req.workspaceId, dto);
+  }
+
+  /**
+   * Update an existing personality
+   */
+  @Put(":id")
+  async update(
+    @Req() req: any,
+    @Param("id") id: string,
+    @Body() dto: UpdatePersonalityDto,
+  ): Promise<Personality> {
+    return this.personalitiesService.update(req.workspaceId, id, dto);
+  }
+
+  /**
+   * Delete a personality
+   */
+  @Delete(":id")
+  async remove(@Req() req: any, @Param("id") id: string): Promise<Personality> {
+    return this.personalitiesService.remove(req.workspaceId, id);
+  }
+}