desktop: add loading window and restructure rust (#12176)

packages/desktop/src-tauri/src/constants.rs

@@ -0,0 +1,10 @@
+use tauri_plugin_window_state::StateFlags;
+
+pub const SETTINGS_STORE: &str = "opencode.settings.dat";
+pub const DEFAULT_SERVER_URL_KEY: &str = "defaultServerUrl";
+pub const UPDATER_ENABLED: bool = option_env!("TAURI_SIGNING_PRIVATE_KEY").is_some();
+pub const MAX_LOG_ENTRIES: usize = 200;
+
+pub fn window_state_flags() -> StateFlags {
+    StateFlags::all() - StateFlags::DECORATIONS - StateFlags::VISIBLE
+}