Add Umami analytics tracking for key user interactions

Integrates Umami analytics with production-only tracking script and event tracking for user login and location creation actions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/ui/SignInButton.tsx

@@ -21,7 +21,7 @@ export const SignInButton:React.FC<{ provider: {id:string, name:string} }> = ({
   const t = useTranslations("login-page");
 
     return(
-        <button className="btn btn-neutral m-1" onClick={() => signIn(provider.id, { callbackUrl:"/home" }) }>
+        <button className="btn btn-neutral m-1" onClick={() => signIn(provider.id, { callbackUrl:"/home" }) } data-umami-event="user-login">
             <Image alt="Provider Logo" loading="lazy" height="24" width="24" id="provider-logo-dark" src={providerLogo(provider)} />
             <span>
                 {t("sign-in-button")} {provider.name}</span>