chore: clean up generated files and update gitignore

- remove api-docs.json from version control
- add src-tauri/gen/ to gitignore

src-tauri/gen/android/.gitignore

@@ -0,0 +1,20 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+build
+/captures
+.externalNativeBuild
+.cxx
+local.properties
+key.properties
+keystore.properties
+
+/.tauri
+/tauri.settings.gradle