fix: remove tauri-plugin-log to avoid logger conflict

`tracing_subscriber::fmt().try_init()` installs a global log
implementation via the tracing-log shim. tauri-plugin-log then
calls `log::set_logger()` which panics with "attempted to set a
logger after the logging system was already initialized".

The plugin was never wired in JS code (no @tauri-apps/plugin-log
import) — backend logging via tracing is sufficient. Drop:
  - tauri-plugin-log dep + plugin registration
  - log:default capability permission
  - @tauri-apps/plugin-log JS dep

Verified: cargo check is clean, app starts past the panic.

src-tauri/src/lib.rs

@@ -21,7 +21,6 @@ pub fn run() {
         .ok();
 
     tauri::Builder::default()
-        .plugin(tauri_plugin_log::Builder::new().build())
         .plugin(tauri_plugin_store::Builder::new().build())
         .plugin(tauri_plugin_shell::init())
         .plugin(tauri_plugin_dialog::init())