refactor: Update Dockerfile.development

Simplify Dockerfile.development by removing redundant file copy and updating comments.

Dockerfile.development

@@ -5,6 +5,9 @@ WORKDIR /code
 # Copy only requirements first to leverage Docker cache
 COPY ./requirements.txt ./
 
+# Copy the main file
+COPY ./main.py ./
+
 # Install dependencies
 RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt
 
@@ -14,8 +17,6 @@ RUN rm -rf ./app/data
 # Copy the rest of the application code
 COPY ./app ./app
 
-# Copy the main file
-COPY ./app.py ./
 
 # Install FastAPI separately to leverage Docker cache
 RUN pip install "fastapi[standard]"