Reorganize project structure

- Move development and test files to dev/ directory
- Update .gitignore to exclude development files
- Update paths in configuration files
- Add new audio-player.js for frontend

database.py

@@ -1,11 +1,14 @@
 # database.py — SQLModel engine/session for PostgreSQL
 
-from sqlmodel import create_engine, Session
+from sqlmodel import create_engine, Session, SQLModel
 import os
 
 POSTGRES_URL = os.getenv("DATABASE_URL", "postgresql://d2s:kuTy4ZKs2VcjgDh6@localhost:5432/dictastream")
 engine = create_engine(POSTGRES_URL, echo=False)
 
+# SQLAlchemy Base class for models
+Base = SQLModel
+
 def get_db():
     with Session(engine) as session:
         yield session