Implement complete nested todo tree web app MVP

This commit implements a fully functional self-hosted task decomposition engine with:

Backend (FastAPI + SQLite):
- RESTful API with full CRUD operations for projects and tasks
- Arbitrary-depth hierarchical task structure using self-referencing parent_task_id
- JSON import endpoint for seeding projects from LLM-generated breakdowns
- SQLAlchemy models with proper relationships and cascade deletes
- Status tracking (backlog, in_progress, blocked, done)
- Auto-generated OpenAPI documentation

Frontend (React + Vite + Tailwind):
- Dark cyberpunk theme with orange accents
- Project list page with create/import/delete functionality
- Dual view modes:
  * Tree View: Collapsible hierarchical display with inline editing
  * Kanban Board: Drag-and-drop status management
- Real-time CRUD operations for tasks and subtasks
- JSON import modal with validation
- Responsive design optimized for desktop

Infrastructure:
- Docker setup with multi-stage builds
- docker-compose for orchestration
- Nginx reverse proxy for production frontend
- Named volume for SQLite persistence
- CORS configuration for local development

Documentation:
- Comprehensive README with setup instructions
- Example JSON import file demonstrating nested structure
- API endpoint documentation
- Data model diagrams

backend/app/schemas.py

@@ -0,0 +1,93 @@
+from pydantic import BaseModel, ConfigDict
+from typing import Optional, List
+from datetime import datetime
+from .models import TaskStatus
+
+
+# Task Schemas
+class TaskBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    status: TaskStatus = TaskStatus.BACKLOG
+    parent_task_id: Optional[int] = None
+    sort_order: int = 0
+
+
+class TaskCreate(TaskBase):
+    project_id: int
+
+
+class TaskUpdate(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    status: Optional[TaskStatus] = None
+    parent_task_id: Optional[int] = None
+    sort_order: Optional[int] = None
+
+
+class Task(TaskBase):
+    id: int
+    project_id: int
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+class TaskWithSubtasks(Task):
+    subtasks: List['TaskWithSubtasks'] = []
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+# Project Schemas
+class ProjectBase(BaseModel):
+    name: str
+    description: Optional[str] = None
+
+
+class ProjectCreate(ProjectBase):
+    pass
+
+
+class ProjectUpdate(BaseModel):
+    name: Optional[str] = None
+    description: Optional[str] = None
+
+
+class Project(ProjectBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+class ProjectWithTasks(Project):
+    tasks: List[Task] = []
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+# JSON Import Schemas
+class ImportSubtask(BaseModel):
+    title: str
+    description: Optional[str] = None
+    status: TaskStatus = TaskStatus.BACKLOG
+    subtasks: List['ImportSubtask'] = []
+
+
+class ImportProject(BaseModel):
+    name: str
+    description: Optional[str] = None
+
+
+class ImportData(BaseModel):
+    project: ImportProject
+    tasks: List[ImportSubtask] = []
+
+
+class ImportResult(BaseModel):
+    project_id: int
+    project_name: str
+    tasks_created: int