fix: Resolve Coolify build failure by fixing requirements.txt PyPI versions, adding gunicorn, and using standard pip in Dockerfile

backend/Dockerfile

@@ -2,19 +2,19 @@ FROM python:3.11-slim
 
 WORKDIR /app
 
-# Install system dependencies
+# Install system dependencies needed for compiling C extensions (psycopg2, pillow, reportlab)
 RUN apt-get update && apt-get install -y --no-install-recommends \
     gcc \
     libpq-dev \
+    libjpeg-dev \
+    zlib1g-dev \
     curl \
     && rm -rf /var/lib/apt/lists/*
 
-# Install uv for fast dependency management
-COPY --from=ghcr.io/astral-sh/uv:latest /uv /bin/uv
-
-# Copy requirements and install via uv
+# Copy requirements and install
 COPY requirements.txt .
-RUN uv pip install --system -r requirements.txt
+RUN pip install --no-cache-dir --upgrade pip && \
+    pip install --no-cache-dir -r requirements.txt
 
 # Copy backend application code
 COPY . .

backend/requirements.txt

@@ -1,15 +1,15 @@
-asgiref==3.12.1
-certifi==2026.7.22
-charset-normalizer==3.4.9
-django==6.0.7
-django-cors-headers==4.9.0
-djangorestframework==3.17.1
-idna==3.18
-pillow==12.3.0
-pip==26.1.2
-psycopg2-binary==2.9.12
-python-dotenv==1.2.2
-reportlab==5.0.0
-requests==2.34.2
-sqlparse==0.5.5
-urllib3==2.7.0
+Django>=5.0,<6.0
+djangorestframework>=3.14.0
+django-cors-headers>=4.0.0
+psycopg2-binary>=2.9.0
+python-dotenv>=1.0.0
+pillow>=10.0.0
+reportlab>=4.0.0
+requests>=2.31.0
+gunicorn>=21.2.0
+asgiref
+certifi
+charset-normalizer
+idna
+sqlparse
+urllib3