Odległość od miejscowości by Datafic

The extension listens for middle-mouse-button clicks (auxclick, button=1) on any webpage. When triggered, it reads the word under the cursor using caretPositionFromPoint, then sends a message to the background script which queries the Nominatim/OpenStreetMap API to find the location's coordinates and calculate the distance from a user-configured base
city (default: Poznań).

No user data is collected or stored externally. The only storage used is browser.storage.sync for the user's chosen base city (name + lat/lon). The Nominatim API is queried with the word the user clicked on.
To test:
1. Install the extension.
2. Open any webpage with city names (e.g. Wikipedia article about Poland).
3. Middle-click on a city name — a tooltip should appear with the distance in km.
4. Click the extension icon to see the current base city.
5. Click "Zmień miasto bazowe" to open settings and change the base city.