feat(tools): harden scheduler speed limiter logs

Modernize the Tools release surfaces for the cross-platform re-release checklist.

- make Speed Limiter presets unit-aware and persist custom removable quick presets

- keep diagnostic logging opt-in on clean installs and honor the saved log state on startup

- stage Scheduler enablement edits without discarding unsaved draft changes

- extend persisted settings and bindings for log opt-in and speed preset state

Verification:

- npm run build

- npm test -- --run src/store/useDownloadStore.test.ts

- cargo test --lib

- cargo test settings --lib

src-tauri/src/settings.rs

@@ -267,6 +267,8 @@ fn default_settings() -> PersistedSettings {
         approved_download_roots: Vec::new(),
         max_concurrent_downloads: 3,
         global_speed_limit: String::new(),
+        speed_limit_preset_values: vec![1.0, 5.0, 10.0],
+        logs_enabled: false,
         is_sidebar_visible: true,
         active_settings_tab: SettingsTab::Downloads,
         scheduler: SchedulerSettings {
@@ -360,6 +362,8 @@ mod tests {
 
         assert_eq!(settings.max_concurrent_downloads, 7);
         assert_eq!(settings.global_speed_limit, "2M");
+        assert_eq!(settings.speed_limit_preset_values, vec![1.0, 5.0, 10.0]);
+        assert!(!settings.logs_enabled);
         assert!(settings.scheduler.enabled);
         assert_eq!(settings.scheduler.start_time, "06:30");
         assert_eq!(settings.scheduler.selected_days, vec![1, 3, 5]);
@@ -381,9 +385,29 @@ mod tests {
 
         assert_eq!(settings.max_concurrent_downloads, 5);
         assert_eq!(settings.global_speed_limit, "512K");
+        assert_eq!(settings.speed_limit_preset_values, vec![1.0, 5.0, 10.0]);
+        assert!(!settings.logs_enabled);
         assert!(!settings.scheduler.enabled);
     }
 
+    #[test]
+    fn decodes_persisted_log_opt_in() {
+        let stored = json!({
+            "state": {
+                "speedLimitPresetValues": [1, 2.5, 8],
+                "logsEnabled": true
+            },
+            "version": 3
+        });
+
+        let settings = decode_stored_settings(&Value::String(stored.to_string())).unwrap();
+
+        assert_eq!(settings.speed_limit_preset_values, vec![1.0, 2.5, 8.0]);
+        assert!(settings.logs_enabled);
+        assert!(!settings.scheduler.enabled);
+        assert!(settings.global_speed_limit.is_empty());
+    }
+
     #[test]
     fn migrates_legacy_location_settings_and_preserves_custom_overrides() {
         let stored = json!({