chore: enhance security configuration across applications

- Add root-level *.json to .gitignore to prevent wallet backup leaks
- Replace wildcard CORS origins with explicit localhost URLs across all apps
- Add OPTIONS method to CORS allowed methods for preflight requests
- Update coordinator database to use absolute path in data/ directory to prevent duplicates
- Add JWT secret validation in coordinator config (must be set via environment)
- Replace deprecated get_session dependency with Session

apps/coordinator-api/src/app/deps.py

@@ -1,21 +1,9 @@
-from typing import Callable, Generator, Annotated
+from typing import Callable, Annotated
 from fastapi import Depends, Header, HTTPException
-from sqlmodel import Session
 
 from .config import settings
 
 
-def get_session() -> Generator[Session, None, None]:
-    """Get database session"""
-    from .database import engine
-    with Session(engine) as session:
-        yield session
-
-
-# Type alias for session dependency
-SessionDep = Annotated[Session, Depends(get_session)]
-
-
 class APIKeyValidator:
     def __init__(self, allowed_keys: list[str]):
         self.allowed_keys = {key.strip() for key in allowed_keys if key}