fix: mini timer window blank due to hash routing mismatch

The app uses createWebHashHistory but the mini timer window was
opened with WebviewUrl::App("/mini-timer") which sets the URL path,
not the hash fragment. Vue Router never matched the route, so the
Dashboard rendered in a 300x64 window (appearing blank). Now loads
root URL and sets window.location.hash via eval. Also shows/focuses
the main window when closing the mini timer.

src-tauri/src/commands.rs

@@ -1132,7 +1132,9 @@ pub fn open_mini_timer(app: tauri::AppHandle) -> Result<(), String> {
         return Ok(());
     }
 
-    tauri::WebviewWindowBuilder::new(&app, "mini-timer", WebviewUrl::App("/mini-timer".into()))
+    // Load root URL — the app uses hash-based routing (createWebHashHistory),
+    // so we set the hash fragment via eval after the window is created.
+    let win = tauri::WebviewWindowBuilder::new(&app, "mini-timer", WebviewUrl::App(Default::default()))
         .title("Timer")
         .inner_size(300.0, 64.0)
         .always_on_top(true)
@@ -1142,6 +1144,9 @@ pub fn open_mini_timer(app: tauri::AppHandle) -> Result<(), String> {
         .build()
         .map_err(|e| e.to_string())?;
 
+    // Navigate Vue Router to the mini-timer route via hash
+    win.eval("window.location.hash = '/mini-timer'").ok();
+
     Ok(())
 }
 
@@ -1150,6 +1155,11 @@ pub fn close_mini_timer(app: tauri::AppHandle) -> Result<(), String> {
     if let Some(window) = app.get_webview_window("mini-timer") {
         window.close().map_err(|e| e.to_string())?;
     }
+    // Show and focus the main window
+    if let Some(main) = app.get_webview_window("main") {
+        main.show().ok();
+        main.set_focus().ok();
+    }
     Ok(())
 }