Add host configuration for backend server and update documentation

- Introduced a new `host` option in `flake.nix` to specify the server's bind address, defaulting to `0.0.0.0`.
- Updated `run.sh` to use the `HOST` environment variable for server binding.
- Modified `config.py` to read the `HOST` from environment variables, defaulting to `0.0.0.0`.
- Enhanced `README.md` with instructions for setting up the `HOST` variable and clarified access details for development and production modes.
- Adjusted `vite.config.ts` to allow frontend access from other computers by default.

README.md

@@ -39,7 +39,7 @@ A web application that visualizes the origin countries of your media collection
 nix develop
 ```
 
-2. Set up environment variables (create `.env` in `backend/`):
+2. Set up backend environment variables (create `.env` in `backend/`):
 ```bash
 POSTGRES_SOCKET_PATH=/run/postgresql
 POSTGRES_DB=jawz
@@ -48,28 +48,51 @@ SONARR_API_KEY=your_sonarr_api_key
 RADARR_API_KEY=your_radarr_api_key
 LIDARR_API_KEY=your_lidarr_api_key
 PORT=8080
+HOST=0.0.0.0  # Use 127.0.0.1 for localhost only
 ```
 
-3. Run database migrations:
+3. (Optional) Set up frontend environment variables (create `.env.local` in `frontend/`):
+```bash
+# Only needed if backend port/host differs from defaults
+VITE_BACKEND_HOST=127.0.0.1
+VITE_BACKEND_PORT=8080
+VITE_PORT=5173
+```
+
+5. Start the backend (in one terminal):
 ```bash
 cd backend
-alembic upgrade head
+# Uses HOST and PORT from .env file (defaults to 0.0.0.0:8080)
+python -m uvicorn main:app --reload --host ${HOST:-0.0.0.0} --port ${PORT:-8080}
 ```
 
-4. Start the backend (in one terminal):
-```bash
-cd backend
-python -m uvicorn main:app --reload --host 127.0.0.1 --port 8080
-```
-
-5. Start the frontend dev server (in another terminal):
+6. Start the frontend dev server (in another terminal):
 ```bash
 cd frontend
 npm install
+# Optional: Set backend URL if different from default
+# export VITE_BACKEND_HOST=127.0.0.1
+# export VITE_BACKEND_PORT=8080
 npm run dev
 ```
 
-6. Open http://localhost:5173 in your browser
+7. Open http://localhost:5173 in your browser (or http://<your-server-ip>:5173 from another computer)
+
+### Development vs Production
+
+**Development Mode:**
+- Backend runs on port 8080 (configurable)
+- Frontend dev server runs on port 5173 (configurable)
+- Frontend proxies API requests to backend
+- Both are accessible from other computers (bound to 0.0.0.0)
+
+**Production Mode (NixOS deployment):**
+- Backend runs on configured port (default 8080)
+- Frontend is built and served as static files by the backend
+- No separate frontend server needed
+- Access via backend URL only
+
+**Note**: The frontend dev server runs on port 5173 by default and proxies API requests to the backend. If you changed the backend port, set `VITE_BACKEND_PORT` environment variable to match. The frontend dev server binds to `0.0.0.0` by default, so it's accessible from other computers.
 
 ## Building
 
@@ -96,6 +119,7 @@ In your `configuration.nix` or a separate module:
   services.moviemap = {
     enable = true;
     port = 8080;
+    host = "0.0.0.0";  # Bind to all interfaces (use "127.0.0.1" for localhost only)
     postgresSocketPath = "/run/postgresql";
     # Secrets can be strings or file paths (for sops-nix integration)
     sonarrApiKey = "/run/secrets/sonarr-api-key";  # or "your_key_here"
@@ -167,7 +191,15 @@ Or simply run migrations once manually, then enable the service.
 sudo nixos-rebuild switch
 ```
 
-The service will be available at `http://127.0.0.1:8080` (configure your reverse proxy to expose it).
+The service will be available at `http://0.0.0.0:8080` (or your server's IP address). If you set `host = "127.0.0.1"`, it will only be accessible from localhost (use a reverse proxy in that case).
+
+**Note**: If you're accessing from another computer, make sure:
+1. The service is bound to `0.0.0.0` (default) or your server's IP address
+2. Your firewall allows incoming connections on the configured port
+3. If using NixOS, you may need to open the port in your firewall configuration:
+   ```nix
+   networking.firewall.allowedTCPPorts = [ 8080 ];
+   ```
 
 ## API Endpoints