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/dto/create-personality.dto.ts

@@ -0,0 +1,43 @@
+import { IsString, IsIn, IsOptional, IsBoolean, MinLength, MaxLength } from "class-validator";
+
+export const FORMALITY_LEVELS = [
+  "VERY_CASUAL",
+  "CASUAL",
+  "NEUTRAL",
+  "FORMAL",
+  "VERY_FORMAL",
+] as const;
+
+export type FormalityLevel = (typeof FORMALITY_LEVELS)[number];
+
+export class CreatePersonalityDto {
+  @IsString()
+  @MinLength(1)
+  @MaxLength(100)
+  name!: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(500)
+  description?: string;
+
+  @IsString()
+  @MinLength(1)
+  @MaxLength(50)
+  tone!: string;
+
+  @IsIn(FORMALITY_LEVELS)
+  formalityLevel!: FormalityLevel;
+
+  @IsString()
+  @MinLength(10)
+  systemPromptTemplate!: string;
+
+  @IsOptional()
+  @IsBoolean()
+  isDefault?: boolean;
+
+  @IsOptional()
+  @IsBoolean()
+  isActive?: boolean;
+}

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

@@ -0,0 +1,2 @@
+export * from "./create-personality.dto";
+export * from "./update-personality.dto";

apps/api/src/personalities/dto/update-personality.dto.ts

@@ -0,0 +1,4 @@
+import { PartialType } from "@nestjs/mapped-types";
+import { CreatePersonalityDto } from "./create-personality.dto";
+
+export class UpdatePersonalityDto extends PartialType(CreatePersonalityDto) {}

apps/api/src/personalities/entities/personality.entity.ts

@@ -0,0 +1,15 @@
+import { Personality as PrismaPersonality, FormalityLevel } from "@prisma/client";
+
+export class Personality implements PrismaPersonality {
+  id!: string;
+  workspaceId!: string;
+  name!: string;
+  description!: string | null;
+  tone!: string;
+  formalityLevel!: FormalityLevel;
+  systemPromptTemplate!: string;
+  isDefault!: boolean;
+  isActive!: boolean;
+  createdAt!: Date;
+  updatedAt!: Date;
+}

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

@@ -0,0 +1,157 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import { Test, TestingModule } from "@nestjs/testing";
+import { PersonalitiesController } from "./personalities.controller";
+import { PersonalitiesService } from "./personalities.service";
+import { AuthGuard } from "../auth/guards/auth.guard";
+import { CreatePersonalityDto, UpdatePersonalityDto } from "./dto";
+
+describe("PersonalitiesController", () => {
+  let controller: PersonalitiesController;
+  let service: PersonalitiesService;
+
+  const mockWorkspaceId = "workspace-123";
+  const mockUserId = "user-123";
+  const mockPersonalityId = "personality-123";
+
+  const mockRequest = {
+    user: { id: mockUserId },
+    workspaceId: mockWorkspaceId,
+  };
+
+  const mockPersonality = {
+    id: mockPersonalityId,
+    workspaceId: mockWorkspaceId,
+    name: "Professional",
+    description: "Professional communication style",
+    tone: "professional",
+    formalityLevel: "FORMAL" as const,
+    systemPromptTemplate: "You are a professional assistant.",
+    isDefault: true,
+    isActive: true,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+  };
+
+  const mockPersonalitiesService = {
+    findAll: vi.fn(),
+    findOne: vi.fn(),
+    findDefault: vi.fn(),
+    create: vi.fn(),
+    update: vi.fn(),
+    remove: vi.fn(),
+  };
+
+  const mockAuthGuard = {
+    canActivate: vi.fn().mockReturnValue(true),
+  };
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [PersonalitiesController],
+      providers: [
+        {
+          provide: PersonalitiesService,
+          useValue: mockPersonalitiesService,
+        },
+      ],
+    })
+      .overrideGuard(AuthGuard)
+      .useValue(mockAuthGuard)
+      .compile();
+
+    controller = module.get<PersonalitiesController>(PersonalitiesController);
+    service = module.get<PersonalitiesService>(PersonalitiesService);
+
+    // Reset mocks
+    vi.clearAllMocks();
+  });
+
+  describe("findAll", () => {
+    it("should return all personalities", async () => {
+      const mockPersonalities = [mockPersonality];
+      mockPersonalitiesService.findAll.mockResolvedValue(mockPersonalities);
+
+      const result = await controller.findAll(mockRequest as any);
+
+      expect(result).toEqual(mockPersonalities);
+      expect(service.findAll).toHaveBeenCalledWith(mockWorkspaceId, true);
+    });
+
+    it("should filter by active status", async () => {
+      mockPersonalitiesService.findAll.mockResolvedValue([mockPersonality]);
+
+      await controller.findAll(mockRequest as any, false);
+
+      expect(service.findAll).toHaveBeenCalledWith(mockWorkspaceId, false);
+    });
+  });
+
+  describe("findOne", () => {
+    it("should return a personality by id", async () => {
+      mockPersonalitiesService.findOne.mockResolvedValue(mockPersonality);
+
+      const result = await controller.findOne(mockRequest as any, mockPersonalityId);
+
+      expect(result).toEqual(mockPersonality);
+      expect(service.findOne).toHaveBeenCalledWith(mockWorkspaceId, mockPersonalityId);
+    });
+  });
+
+  describe("findDefault", () => {
+    it("should return the default personality", async () => {
+      mockPersonalitiesService.findDefault.mockResolvedValue(mockPersonality);
+
+      const result = await controller.findDefault(mockRequest as any);
+
+      expect(result).toEqual(mockPersonality);
+      expect(service.findDefault).toHaveBeenCalledWith(mockWorkspaceId);
+    });
+  });
+
+  describe("create", () => {
+    const createDto: CreatePersonalityDto = {
+      name: "Casual",
+      description: "Casual communication style",
+      tone: "casual",
+      formalityLevel: "CASUAL",
+      systemPromptTemplate: "You are a casual assistant.",
+    };
+
+    it("should create a new personality", async () => {
+      const newPersonality = { ...mockPersonality, ...createDto, id: "new-id" };
+      mockPersonalitiesService.create.mockResolvedValue(newPersonality);
+
+      const result = await controller.create(mockRequest as any, createDto);
+
+      expect(result).toEqual(newPersonality);
+      expect(service.create).toHaveBeenCalledWith(mockWorkspaceId, createDto);
+    });
+  });
+
+  describe("update", () => {
+    const updateDto: UpdatePersonalityDto = {
+      description: "Updated description",
+    };
+
+    it("should update a personality", async () => {
+      const updatedPersonality = { ...mockPersonality, ...updateDto };
+      mockPersonalitiesService.update.mockResolvedValue(updatedPersonality);
+
+      const result = await controller.update(mockRequest as any, mockPersonalityId, updateDto);
+
+      expect(result).toEqual(updatedPersonality);
+      expect(service.update).toHaveBeenCalledWith(mockWorkspaceId, mockPersonalityId, updateDto);
+    });
+  });
+
+  describe("remove", () => {
+    it("should delete a personality", async () => {
+      mockPersonalitiesService.remove.mockResolvedValue(mockPersonality);
+
+      const result = await controller.remove(mockRequest as any, mockPersonalityId);
+
+      expect(result).toEqual(mockPersonality);
+      expect(service.remove).toHaveBeenCalledWith(mockWorkspaceId, mockPersonalityId);
+    });
+  });
+});

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);
+  }
+}

apps/api/src/personalities/personalities.module.ts

@@ -0,0 +1,13 @@
+import { Module } from "@nestjs/common";
+import { PrismaModule } from "../prisma/prisma.module";
+import { AuthModule } from "../auth/auth.module";
+import { PersonalitiesService } from "./personalities.service";
+import { PersonalitiesController } from "./personalities.controller";
+
+@Module({
+  imports: [PrismaModule, AuthModule],
+  controllers: [PersonalitiesController],
+  providers: [PersonalitiesService],
+  exports: [PersonalitiesService],
+})
+export class PersonalitiesModule {}

apps/api/src/personalities/personalities.service.spec.ts

@@ -0,0 +1,255 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import { Test, TestingModule } from "@nestjs/testing";
+import { PersonalitiesService } from "./personalities.service";
+import { PrismaService } from "../prisma/prisma.service";
+import { CreatePersonalityDto, UpdatePersonalityDto } from "./dto";
+import { NotFoundException, ConflictException } from "@nestjs/common";
+
+describe("PersonalitiesService", () => {
+  let service: PersonalitiesService;
+  let prisma: PrismaService;
+
+  const mockWorkspaceId = "workspace-123";
+  const mockUserId = "user-123";
+  const mockPersonalityId = "personality-123";
+
+  const mockPersonality = {
+    id: mockPersonalityId,
+    workspaceId: mockWorkspaceId,
+    name: "Professional",
+    description: "Professional communication style",
+    tone: "professional",
+    formalityLevel: "FORMAL" as const,
+    systemPromptTemplate: "You are a professional assistant.",
+    isDefault: true,
+    isActive: true,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+  };
+
+  const mockPrismaService = {
+    personality: {
+      findMany: vi.fn(),
+      findUnique: vi.fn(),
+      findFirst: vi.fn(),
+      create: vi.fn(),
+      update: vi.fn(),
+      delete: vi.fn(),
+      count: vi.fn(),
+    },
+    $transaction: vi.fn((callback) => callback(mockPrismaService)),
+  };
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        PersonalitiesService,
+        {
+          provide: PrismaService,
+          useValue: mockPrismaService,
+        },
+      ],
+    }).compile();
+
+    service = module.get<PersonalitiesService>(PersonalitiesService);
+    prisma = module.get<PrismaService>(PrismaService);
+
+    // Reset mocks
+    vi.clearAllMocks();
+  });
+
+  describe("findAll", () => {
+    it("should return all personalities for a workspace", async () => {
+      const mockPersonalities = [mockPersonality];
+      mockPrismaService.personality.findMany.mockResolvedValue(mockPersonalities);
+
+      const result = await service.findAll(mockWorkspaceId);
+
+      expect(result).toEqual(mockPersonalities);
+      expect(prisma.personality.findMany).toHaveBeenCalledWith({
+        where: { workspaceId: mockWorkspaceId, isActive: true },
+        orderBy: [{ isDefault: "desc" }, { name: "asc" }],
+      });
+    });
+
+    it("should filter by active status", async () => {
+      mockPrismaService.personality.findMany.mockResolvedValue([mockPersonality]);
+
+      await service.findAll(mockWorkspaceId, false);
+
+      expect(prisma.personality.findMany).toHaveBeenCalledWith({
+        where: { workspaceId: mockWorkspaceId, isActive: false },
+        orderBy: [{ isDefault: "desc" }, { name: "asc" }],
+      });
+    });
+  });
+
+  describe("findOne", () => {
+    it("should return a personality by id", async () => {
+      mockPrismaService.personality.findUnique.mockResolvedValue(mockPersonality);
+
+      const result = await service.findOne(mockWorkspaceId, mockPersonalityId);
+
+      expect(result).toEqual(mockPersonality);
+      expect(prisma.personality.findUnique).toHaveBeenCalledWith({
+        where: {
+          id: mockPersonalityId,
+          workspaceId: mockWorkspaceId,
+        },
+      });
+    });
+
+    it("should throw NotFoundException when personality not found", async () => {
+      mockPrismaService.personality.findUnique.mockResolvedValue(null);
+
+      await expect(service.findOne(mockWorkspaceId, mockPersonalityId)).rejects.toThrow(
+        NotFoundException,
+      );
+    });
+  });
+
+  describe("findDefault", () => {
+    it("should return the default personality", async () => {
+      mockPrismaService.personality.findFirst.mockResolvedValue(mockPersonality);
+
+      const result = await service.findDefault(mockWorkspaceId);
+
+      expect(result).toEqual(mockPersonality);
+      expect(prisma.personality.findFirst).toHaveBeenCalledWith({
+        where: { workspaceId: mockWorkspaceId, isDefault: true, isActive: true },
+      });
+    });
+
+    it("should throw NotFoundException when no default personality exists", async () => {
+      mockPrismaService.personality.findFirst.mockResolvedValue(null);
+
+      await expect(service.findDefault(mockWorkspaceId)).rejects.toThrow(NotFoundException);
+    });
+  });
+
+  describe("create", () => {
+    const createDto: CreatePersonalityDto = {
+      name: "Casual",
+      description: "Casual communication style",
+      tone: "casual",
+      formalityLevel: "CASUAL",
+      systemPromptTemplate: "You are a casual assistant.",
+    };
+
+    it("should create a new personality", async () => {
+      mockPrismaService.personality.findFirst.mockResolvedValue(null);
+      mockPrismaService.personality.create.mockResolvedValue({
+        ...mockPersonality,
+        ...createDto,
+        id: "new-personality-id",
+      });
+
+      const result = await service.create(mockWorkspaceId, createDto);
+
+      expect(result).toMatchObject(createDto);
+      expect(prisma.personality.create).toHaveBeenCalledWith({
+        data: {
+          workspaceId: mockWorkspaceId,
+          ...createDto,
+        },
+      });
+    });
+
+    it("should throw ConflictException when name already exists", async () => {
+      mockPrismaService.personality.findFirst.mockResolvedValue(mockPersonality);
+
+      await expect(service.create(mockWorkspaceId, createDto)).rejects.toThrow(ConflictException);
+    });
+
+    it("should unset other defaults when creating a new default personality", async () => {
+      const createDefaultDto = { ...createDto, isDefault: true };
+      // First call to findFirst checks for name conflict (should be null)
+      // Second call to findFirst finds the existing default personality
+      mockPrismaService.personality.findFirst
+        .mockResolvedValueOnce(null) // No name conflict
+        .mockResolvedValueOnce(mockPersonality); // Existing default
+      mockPrismaService.personality.update.mockResolvedValue({
+        ...mockPersonality,
+        isDefault: false,
+      });
+      mockPrismaService.personality.create.mockResolvedValue({
+        ...mockPersonality,
+        ...createDefaultDto,
+      });
+
+      await service.create(mockWorkspaceId, createDefaultDto);
+
+      expect(prisma.personality.update).toHaveBeenCalledWith({
+        where: { id: mockPersonalityId },
+        data: { isDefault: false },
+      });
+    });
+  });
+
+  describe("update", () => {
+    const updateDto: UpdatePersonalityDto = {
+      description: "Updated description",
+      tone: "updated",
+    };
+
+    it("should update a personality", async () => {
+      mockPrismaService.personality.findUnique.mockResolvedValue(mockPersonality);
+      mockPrismaService.personality.findFirst.mockResolvedValue(null);
+      mockPrismaService.personality.update.mockResolvedValue({
+        ...mockPersonality,
+        ...updateDto,
+      });
+
+      const result = await service.update(mockWorkspaceId, mockPersonalityId, updateDto);
+
+      expect(result).toMatchObject(updateDto);
+      expect(prisma.personality.update).toHaveBeenCalledWith({
+        where: { id: mockPersonalityId },
+        data: updateDto,
+      });
+    });
+
+    it("should throw NotFoundException when personality not found", async () => {
+      mockPrismaService.personality.findUnique.mockResolvedValue(null);
+
+      await expect(
+        service.update(mockWorkspaceId, mockPersonalityId, updateDto),
+      ).rejects.toThrow(NotFoundException);
+    });
+
+    it("should throw ConflictException when updating to existing name", async () => {
+      const updateNameDto = { name: "Existing Name" };
+      mockPrismaService.personality.findUnique.mockResolvedValue(mockPersonality);
+      mockPrismaService.personality.findFirst.mockResolvedValue({
+        ...mockPersonality,
+        id: "different-id",
+      });
+
+      await expect(
+        service.update(mockWorkspaceId, mockPersonalityId, updateNameDto),
+      ).rejects.toThrow(ConflictException);
+    });
+  });
+
+  describe("remove", () => {
+    it("should delete a personality", async () => {
+      mockPrismaService.personality.findUnique.mockResolvedValue(mockPersonality);
+      mockPrismaService.personality.delete.mockResolvedValue(mockPersonality);
+
+      const result = await service.remove(mockWorkspaceId, mockPersonalityId);
+
+      expect(result).toEqual(mockPersonality);
+      expect(prisma.personality.delete).toHaveBeenCalledWith({
+        where: { id: mockPersonalityId },
+      });
+    });
+
+    it("should throw NotFoundException when personality not found", async () => {
+      mockPrismaService.personality.findUnique.mockResolvedValue(null);
+
+      await expect(service.remove(mockWorkspaceId, mockPersonalityId)).rejects.toThrow(
+        NotFoundException,
+      );
+    });
+  });
+});

apps/api/src/personalities/personalities.service.ts

@@ -0,0 +1,156 @@
+import {
+  Injectable,
+  NotFoundException,
+  ConflictException,
+  Logger,
+} from "@nestjs/common";
+import { PrismaService } from "../prisma/prisma.service";
+import { CreatePersonalityDto, UpdatePersonalityDto } from "./dto";
+import { Personality } from "./entities/personality.entity";
+
+@Injectable()
+export class PersonalitiesService {
+  private readonly logger = new Logger(PersonalitiesService.name);
+
+  constructor(private readonly prisma: PrismaService) {}
+
+  /**
+   * Find all personalities for a workspace
+   */
+  async findAll(workspaceId: string, isActive: boolean = true): Promise<Personality[]> {
+    return this.prisma.personality.findMany({
+      where: { workspaceId, isActive },
+      orderBy: [{ isDefault: "desc" }, { name: "asc" }],
+    });
+  }
+
+  /**
+   * Find a specific personality by ID
+   */
+  async findOne(workspaceId: string, id: string): Promise<Personality> {
+    const personality = await this.prisma.personality.findUnique({
+      where: { id, workspaceId },
+    });
+
+    if (!personality) {
+      throw new NotFoundException(`Personality with ID ${id} not found`);
+    }
+
+    return personality;
+  }
+
+  /**
+   * Find the default personality for a workspace
+   */
+  async findDefault(workspaceId: string): Promise<Personality> {
+    const personality = await this.prisma.personality.findFirst({
+      where: { workspaceId, isDefault: true, isActive: true },
+    });
+
+    if (!personality) {
+      throw new NotFoundException(`No default personality found for workspace ${workspaceId}`);
+    }
+
+    return personality;
+  }
+
+  /**
+   * Create a new personality
+   */
+  async create(workspaceId: string, dto: CreatePersonalityDto): Promise<Personality> {
+    // Check for duplicate name
+    const existing = await this.prisma.personality.findFirst({
+      where: { workspaceId, name: dto.name },
+    });
+
+    if (existing) {
+      throw new ConflictException(`Personality with name "${dto.name}" already exists`);
+    }
+
+    // If creating a default personality, unset other defaults
+    if (dto.isDefault) {
+      await this.unsetOtherDefaults(workspaceId);
+    }
+
+    const personality = await this.prisma.personality.create({
+      data: {
+        workspaceId,
+        ...dto,
+      },
+    });
+
+    this.logger.log(`Created personality ${personality.id} for workspace ${workspaceId}`);
+    return personality;
+  }
+
+  /**
+   * Update an existing personality
+   */
+  async update(
+    workspaceId: string,
+    id: string,
+    dto: UpdatePersonalityDto,
+  ): Promise<Personality> {
+    // Check existence
+    await this.findOne(workspaceId, id);
+
+    // Check for duplicate name if updating name
+    if (dto.name) {
+      const existing = await this.prisma.personality.findFirst({
+        where: { workspaceId, name: dto.name, id: { not: id } },
+      });
+
+      if (existing) {
+        throw new ConflictException(`Personality with name "${dto.name}" already exists`);
+      }
+    }
+
+    // If setting as default, unset other defaults
+    if (dto.isDefault === true) {
+      await this.unsetOtherDefaults(workspaceId, id);
+    }
+
+    const personality = await this.prisma.personality.update({
+      where: { id },
+      data: dto,
+    });
+
+    this.logger.log(`Updated personality ${id} for workspace ${workspaceId}`);
+    return personality;
+  }
+
+  /**
+   * Delete a personality
+   */
+  async remove(workspaceId: string, id: string): Promise<Personality> {
+    // Check existence
+    await this.findOne(workspaceId, id);
+
+    const personality = await this.prisma.personality.delete({
+      where: { id },
+    });
+
+    this.logger.log(`Deleted personality ${id} from workspace ${workspaceId}`);
+    return personality;
+  }
+
+  /**
+   * Unset the default flag on all other personalities in the workspace
+   */
+  private async unsetOtherDefaults(workspaceId: string, excludeId?: string): Promise<void> {
+    const currentDefault = await this.prisma.personality.findFirst({
+      where: {
+        workspaceId,
+        isDefault: true,
+        ...(excludeId && { id: { not: excludeId } }),
+      },
+    });
+
+    if (currentDefault) {
+      await this.prisma.personality.update({
+        where: { id: currentDefault.id },
+        data: { isDefault: false },
+      });
+    }
+  }
+}