refactor: rename backend/frontend dirs and remove NovelWriter submodule

- Rename qwen3-tts-backend → canto-backend
- Rename qwen3-tts-frontend → canto-frontend
- Remove NovelWriter embedded repo

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

canto-backend/schemas/job.py

@@ -0,0 +1,25 @@
+from datetime import datetime
+from typing import Optional, Dict, Any, List
+from pydantic import BaseModel, ConfigDict
+
+class JobBase(BaseModel):
+    job_type: str
+
+class JobCreate(JobBase):
+    input_data: Dict[str, Any]
+
+class Job(JobBase):
+    id: int
+    user_id: int
+    status: str
+    output_path: Optional[str] = None
+    download_url: Optional[str] = None
+    error_message: Optional[str] = None
+    created_at: datetime
+    completed_at: Optional[datetime] = None
+
+    model_config = ConfigDict(from_attributes=True)
+
+class JobList(BaseModel):
+    total: int
+    jobs: List[Job]