feat: add fastAPI submodule and migrate pad_scanner to CargoTrace org

- Add apps/fastAPI as submodule pointing to CargoTrace/fastAPI
- Update pad_scanner remote URL from admin to CargoTrace org

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "apps/pad_scanner"]
 	path = apps/pad_scanner
-	url = git@gitea.server10086.icu:admin/pad_scanner.git
+	url = git@gitea.server10086.icu:CargoTrace/pad_scanner.git
+[submodule "apps/fastAPI"]
+	path = apps/fastAPI
+	url = git@gitea.server10086.icu:CargoTrace/fastAPI.git