`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.