feat(#5): Implement CRUD APIs for tasks, events, and projects

Implements comprehensive CRUD APIs following TDD principles with 92.44%
test coverage (exceeds 85% requirement).

Features:
- Tasks API: Full CRUD with filtering, pagination, and subtask support
- Events API: Full CRUD with recurrence support and date filtering
- Projects API: Full CRUD with task/event association
- Authentication guards on all endpoints
- Workspace-scoped queries for multi-tenant isolation
- Activity logging for all operations (CREATED, UPDATED, DELETED, etc.)
- DTOs with class-validator validation
- Comprehensive test suite (221 tests, 44 for new APIs)

Implementation:
- Services: Business logic with Prisma ORM integration
- Controllers: RESTful endpoints with AuthGuard
- Modules: Properly registered in AppModule
- Documentation: Complete API reference in docs/4-api/4-crud-endpoints/

Test Coverage:
- Tasks: 96.1%
- Events: 89.83%
- Projects: 84.21%
- Overall: 92.44%

TDD Workflow:
1. RED: Wrote failing tests first
2. GREEN: Implemented minimal code to pass tests
3. REFACTOR: Improved code quality while maintaining coverage

Refs #5

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

apps/api/src/projects/projects.module.ts

@@ -0,0 +1,14 @@
+import { Module } from "@nestjs/common";
+import { ProjectsController } from "./projects.controller";
+import { ProjectsService } from "./projects.service";
+import { PrismaModule } from "../prisma/prisma.module";
+import { ActivityModule } from "../activity/activity.module";
+import { AuthModule } from "../auth/auth.module";
+
+@Module({
+  imports: [PrismaModule, ActivityModule, AuthModule],
+  controllers: [ProjectsController],
+  providers: [ProjectsService],
+  exports: [ProjectsService],
+})
+export class ProjectsModule {}