feat(gitea): add optional internal URL for Gitea integration

- Introduced a new field `giteaInternalUrl` in the Gitea provider settings to allow users to specify an internal URL for OAuth token exchange when Gitea runs on the same instance as Dokploy.
- Updated the Gitea provider forms to include the new field with appropriate descriptions.
- Modified the token exchange logic to utilize the internal URL if provided, enhancing connectivity options for users.
- Updated database schema to accommodate the new field.

packages/server/src/utils/providers/gitea.ts

@@ -49,7 +49,9 @@ export const refreshGiteaToken = async (giteaProviderId: string) => {
 		}
 
 		// Token is expired or about to expire, refresh it
-		const tokenEndpoint = `${giteaProvider.giteaUrl}/login/oauth/access_token`;
+		// Use internal URL when Gitea is on same instance as Dokploy
+		const baseUrl = giteaProvider.giteaInternalUrl || giteaProvider.giteaUrl;
+		const tokenEndpoint = `${baseUrl}/login/oauth/access_token`;
 		const params = new URLSearchParams({
 			grant_type: "refresh_token",
 			refresh_token: giteaProvider.refreshToken,