chore(config): add Tauri generated files to .gitignore

Add **/src-tauri/gen/ pattern to ignore Tauri-generated files
(icons, capabilities, schemas) that should not be committed.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: doublegate

.gitignore

@@ -68,6 +68,9 @@ clients/*/src-tauri/target/
 clients/wraith-ios/wraith-swift-ffi/target/
 clients/wraith-android/app/src/main/rust/target/
 
+# Tauri generated files
+**/src-tauri/gen/
+
 # Node.js
 **/node_modules/
 npm-debug.log*