refactor(environment): update virtualenv path to /opt/venv in Docker setup

- Adjusted `docker-compose.dev.yml` to reflect the new venv location.
- Modified entrypoint script and Dockerfile to reference `/opt/venv` for isolated dependencies.
- Improved bind mount setup to prevent venv overwrites during development.

backend/Dockerfile

@@ -7,7 +7,10 @@ ENV PYTHONDONTWRITEBYTECODE=1 \
     PYTHONPATH=/app \
     UV_COMPILE_BYTECODE=1 \
     UV_LINK_MODE=copy \
-    UV_NO_CACHE=1
+    UV_NO_CACHE=1 \
+    UV_PROJECT_ENVIRONMENT=/opt/venv \
+    VIRTUAL_ENV=/opt/venv \
+    PATH="/opt/venv/bin:$PATH"
 
 # Install system dependencies and uv
 RUN apt-get update && \
@@ -20,7 +23,7 @@ RUN apt-get update && \
 # Copy dependency files
 COPY pyproject.toml uv.lock ./
 
-# Install dependencies using uv (development mode with dev dependencies)
+# Install dependencies using uv into /opt/venv (outside /app to survive bind mounts)
 RUN uv sync --extra dev --frozen
 
 # Copy application code
@@ -45,7 +48,10 @@ ENV PYTHONDONTWRITEBYTECODE=1 \
     PYTHONPATH=/app \
     UV_COMPILE_BYTECODE=1 \
     UV_LINK_MODE=copy \
-    UV_NO_CACHE=1
+    UV_NO_CACHE=1 \
+    UV_PROJECT_ENVIRONMENT=/opt/venv \
+    VIRTUAL_ENV=/opt/venv \
+    PATH="/opt/venv/bin:$PATH"
 
 # Install system dependencies and uv
 RUN apt-get update && \
@@ -58,7 +64,7 @@ RUN apt-get update && \
 # Copy dependency files
 COPY pyproject.toml uv.lock ./
 
-# Install only production dependencies using uv (no dev dependencies)
+# Install only production dependencies using uv into /opt/venv
 RUN uv sync --frozen --no-dev
 
 # Copy application code
@@ -67,7 +73,7 @@ COPY entrypoint.sh /usr/local/bin/
 RUN chmod +x /usr/local/bin/entrypoint.sh
 
 # Set ownership to non-root user
-RUN chown -R appuser:appuser /app
+RUN chown -R appuser:appuser /app /opt/venv
 
 # Switch to non-root user
 USER appuser
@@ -77,4 +83,4 @@ HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
     CMD curl -f http://localhost:8000/health || exit 1
 
 ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]
-CMD ["uv", "run", "uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]
+CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]

backend/entrypoint.sh

@@ -1,11 +1,11 @@
 #!/bin/bash
 set -e
 
-# Ensure the project's virtualenv binaries are on PATH so commands like
-# 'uvicorn' work even when not prefixed by 'uv run'. This matches how uv
-# installs the env into /app/.venv in our containers.
-if [ -d "/app/.venv/bin" ]; then
-  export PATH="/app/.venv/bin:$PATH"
+# Ensure the virtualenv binaries are on PATH. Dependencies are installed
+# to /opt/venv (not /app/.venv) to survive bind mounts in development.
+if [ -d "/opt/venv/bin" ]; then
+  export PATH="/opt/venv/bin:$PATH"
+  export VIRTUAL_ENV="/opt/venv"
 fi
 
 # Only the backend service should run migrations and init_db

docker-compose.dev.yml

@@ -40,8 +40,7 @@ services:
     volumes:
       - ./backend:/app
       - ./uploads:/app/uploads
-      # Exclude local .venv from bind mount to use container's .venv
-      - /app/.venv
+      # Note: venv is at /opt/venv (not /app/.venv) so bind mount doesn't affect it
     ports:
       - "8000:8000"
     env_file:
@@ -76,7 +75,6 @@ services:
       target: development
     volumes:
       - ./backend:/app
-      - /app/.venv
     env_file:
       - .env
     environment:
@@ -99,7 +97,6 @@ services:
       target: development
     volumes:
       - ./backend:/app
-      - /app/.venv
     env_file:
       - .env
     environment:
@@ -122,7 +119,6 @@ services:
       target: development
     volumes:
       - ./backend:/app
-      - /app/.venv
     env_file:
       - .env
     environment:
@@ -145,7 +141,6 @@ services:
       target: development
     volumes:
       - ./backend:/app
-      - /app/.venv
     env_file:
       - .env
     environment: