feat: migrate logs API from REST to IPC streaming (#4277)

* feat: migrate logs API from REST to IPC streaming

- Replace REST API `/logs` calls with IPC streaming implementation
- Add new `src-tauri/src/ipc/logs.rs` with `LogsMonitor` for real-time log streaming
- Implement duplicate stream prevention with level tracking
- Add frontend-backend communication via Tauri commands for log management
- Remove WebSocket compatibility, maintain IPC-only mode
- Fix duplicate monitoring task startup when toggling log service
- Add proper task lifecycle management with JoinHandle cleanup

* refactor: remove dead code from logs.rs to fix clippy warnings

- Remove unused `timestamp` field from LogItem struct
- Remove unused `client` field from LogsMonitor struct
- Remove unused methods: `is_fresh`, `get_current_monitoring_level`, `get_current_logs`
- Simplify LogsMonitor initialization by removing client dependency
- All clippy warnings with -D warnings now resolved

* refactor: extract duplicate fmt_bytes function to utils module

- Create new utils/format.rs module with fmt_bytes function
- Remove duplicate fmt_bytes implementations from traffic.rs and memory.rs
- Update imports to use shared utils::format::fmt_bytes
- Add comprehensive unit tests for fmt_bytes function
- Ensure DRY principle compliance and code maintainability

src/pages/_layout.tsx

@@ -184,7 +184,7 @@ const Layout = () => {
   useEffect(() => {
     if (clashInfo) {
       const { server = "", secret = "" } = clashInfo;
-      initGlobalLogService(server, secret, enableLog, "info");
+      initGlobalLogService(enableLog, "info");
     }
   }, [clashInfo, enableLog]);
 

src/pages/logs.tsx

@@ -71,18 +71,12 @@ const LogPage = () => {
 
   const handleLogLevelChange = (newLevel: LogLevel) => {
     setLogLevel(newLevel);
-    if (clashInfo) {
-      const { server = "", secret = "" } = clashInfo;
-      changeLogLevel(newLevel, server, secret);
-    }
+    changeLogLevel(newLevel);
   };
 
   const handleToggleLog = () => {
-    if (clashInfo) {
-      const { server = "", secret = "" } = clashInfo;
-      toggleLogEnabled(server, secret);
-      setEnableLog(!enableLog);
-    }
+    toggleLogEnabled();
+    setEnableLog(!enableLog);
   };
 
   return (