feat: add unified linting scripts and git hooks for code quality enforcement

- Introduced `lint` and `lint-fix` applications in `flake.nix` for unified linting of backend (Python) and frontend (TypeScript/Svelte) code.
- Added `scripts/lint.sh` for manual linting execution.
- Created `scripts/install-hooks.sh` to set up git hooks for automatic linting before commits and optional tests before pushes.
- Updated `README.md` with instructions for using the new linting features and git hooks.

backend/app/core/schemas.py

@@ -10,13 +10,7 @@ from pydantic import BaseModel, ConfigDict, Field
 class BaseSchema(BaseModel):
     """Base schema with common configuration."""
 
-    model_config = ConfigDict(
-        from_attributes=True,
-        populate_by_name=True,
-        json_schema_extra={
-            "example": {}
-        }
-    )
+    model_config = ConfigDict(from_attributes=True, populate_by_name=True, json_schema_extra={"example": {}})
 
 
 class TimestampSchema(BaseSchema):
@@ -61,4 +55,3 @@ class PaginatedResponse(BaseSchema):
 
     items: list[Any] = Field(..., description="List of items")
     pagination: PaginationSchema = Field(..., description="Pagination metadata")
-