debug: add file-based startup log to diagnose silent crash

Writes to %APPDATA%\Wraith\wraith-startup.log since release
builds suppress all console output via windows_subsystem.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src-tauri/src/lib.rs

@@ -104,9 +104,30 @@ pub fn data_directory() -> PathBuf {
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
+    // Debug log to file — release builds hide console output via windows_subsystem = "windows"
+    let log_path = data_directory().join("wraith-startup.log");
+    let _ = std::fs::create_dir_all(data_directory());
+    let log = |msg: &str| {
+        use std::io::Write;
+        if let Ok(mut f) = std::fs::OpenOptions::new().create(true).append(true).open(&log_path) {
+            let _ = writeln!(f, "{}", msg);
+        }
+    };
+
+    log("=== Wraith starting ===");
     let data_dir = data_directory();
-    let app_state = AppState::new(data_dir)
-        .expect("Failed to initialize application state");
+    log(&format!("Data dir: {:?}", data_dir));
+
+    let app_state = match AppState::new(data_dir) {
+        Ok(state) => {
+            log("AppState initialized OK");
+            state
+        }
+        Err(e) => {
+            log(&format!("FATAL: AppState init failed: {}", e));
+            return;
+        }
+    };
 
     // Seed built-in themes (INSERT OR IGNORE — safe to call on every boot).
     app_state.theme.seed_builtins();
@@ -125,6 +146,8 @@ pub fn run() {
         }
     }
 
+    log("Building Tauri app...");
+
     tauri::Builder::default()
         .plugin(tauri_plugin_shell::init())
         .plugin(tauri_plugin_updater::Builder::new().build())
@@ -172,5 +195,7 @@ pub fn run() {
             commands::theme_commands::get_theme,
         ])
         .run(tauri::generate_context!())
-        .expect("error while running tauri application");
+        .unwrap_or_else(|e| {
+            log(&format!("FATAL: Tauri run failed: {}", e));
+        });
 }