docs: correct the Python tabs' data directory, and document the serve options, secret key file, and single-worker migrations

docs/getting-started/quick-start/tab-python/Conda.md

@@ -38,7 +38,7 @@ If your terminal says the command doesn't exist:
     ```
 
 2.  **Remove Data (WARNING: Deletes all data):**
-    Delete your data directory (usually `~/.open-webui` unless configured otherwise):
+    Without `DATA_DIR`, the data directory sits inside the environment (`.../site-packages/open_webui/data`), so removing the environment above already deletes it. If you set `DATA_DIR`, delete that directory:
     ```bash
     rm -rf ~/.open-webui
     ```

docs/getting-started/quick-start/tab-python/Pip.md

@@ -3,11 +3,13 @@ pip install open-webui
 open-webui serve
 ```
 
-Open WebUI is now on [http://localhost:8080](http://localhost:8080). Set `DATA_DIR` to choose where your data lives, for example `DATA_DIR=~/.open-webui open-webui serve`.
+Open WebUI is now on [http://localhost:8080](http://localhost:8080). Set `DATA_DIR` to choose where your data lives, for example `DATA_DIR=~/.open-webui open-webui serve`. Use `--host` and `--port` to change the bind address, for example `open-webui serve --port 3000`.
+
+The command signs sessions with a key it writes to `.webui_secret_key` in the directory you start it from. Set `WEBUI_SECRET_KEY` in the environment, or always start from the same directory; a new key signs everyone out.
 
 **Command not found?** Activate the environment you installed into; the `open-webui` command lives in its `bin` folder (`Scripts` on Windows).
 
-**Need a fix that is not released yet?** PyPI carries releases only. Run the Docker `:dev` image beside your install with its own volume, or run from the `dev` branch as described in [Developing Open WebUI](/getting-started/advanced-topics/development).
+**Need a fix that is not released yet?** PyPI carries releases only. Run the Docker `:dev` image beside your install with its own volume, or run from the `dev` branch as described in [Developing Open WebUI](/getting-started/advanced-topics/development). Installing from a source checkout or a Git URL runs the build hook, which needs Node.js and npm to build the frontend; the PyPI wheel does not.
 
 ## Uninstall
 
@@ -17,7 +19,7 @@ Open WebUI is now on [http://localhost:8080](http://localhost:8080). Set `DATA_D
     pip uninstall open-webui
     ```
 
-2. **Remove data (optional, deletes all data):**
+2. **Remove data (optional, deletes all data):** delete the directory you set as `DATA_DIR`. Without it, the data is in `site-packages/open_webui/data` inside the environment, which `pip uninstall` leaves in place because it was created at run time.
     ```bash
     rm -rf ~/.open-webui
     ```

docs/getting-started/quick-start/tab-python/PythonUpdating.md

@@ -22,6 +22,8 @@ If you run Open WebUI with `UVICORN_WORKERS > 1` (e.g., in a production environm
 2. Start the application with `UVICORN_WORKERS=1` environment variable set.
 3. Wait for the application to fully start and complete migrations.
 4. Stop and restart the application with your desired number of workers.
+
+Migrations run at import time in every worker. As an alternative, set `ENABLE_DB_MIGRATIONS=false` on every worker or replica except one, so only that one ever runs them.
 :::
 
 For version pinning, rollback, and backup procedures, see the [full update guide](/getting-started/updating).

docs/getting-started/quick-start/tab-python/Uv.md

@@ -57,7 +57,7 @@ To remove Open WebUI when running with `uvx`:
     ```
 
 4.  **Remove Data (WARNING: Deletes all data):**
-    Delete your data directory (default is `~/.open-webui` or the path set in `DATA_DIR`):
+    Delete the directory you set as `DATA_DIR`. Without it, the data was inside the cached tool environment cleared above, which is why the tip at the top tells you to set one:
     ```bash
     rm -rf ~/.open-webui
     ```

docs/getting-started/quick-start/tab-python/Venv.md

@@ -51,7 +51,7 @@ If your terminal says the command doesn't exist:
     ```
 
 2.  **Remove Data (WARNING: Deletes all data):**
-    Delete your data directory (usually `~/.open-webui` unless configured otherwise):
+    Without `DATA_DIR`, the data directory sits inside the venv (`.../site-packages/open_webui/data`), so removing the `venv` folder above already deletes it. If you set `DATA_DIR`, delete that directory:
     ```bash
     rm -rf ~/.open-webui
     ```