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/services/ipc-log-service.ts

@@ -0,0 +1,63 @@
+// IPC-based log service using Tauri commands with streaming support
+import {
+  getClashLogs,
+  startLogsMonitoring,
+  clearLogs as clearLogsCmd,
+} from "@/services/cmds";
+import dayjs from "dayjs";
+
+export type LogLevel = "warning" | "info" | "debug" | "error" | "all";
+
+export interface ILogItem {
+  time?: string;
+  type: string;
+  payload: string;
+  [key: string]: any;
+}
+
+// Start logs monitoring with specified level
+export const startLogsStreaming = async (logLevel: LogLevel = "info") => {
+  try {
+    const level = logLevel === "all" ? undefined : logLevel;
+    await startLogsMonitoring(level);
+    console.log(
+      `[IPC-LogService] Started logs monitoring with level: ${logLevel}`,
+    );
+  } catch (error) {
+    console.error("[IPC-LogService] Failed to start logs monitoring:", error);
+  }
+};
+
+// Fetch logs using IPC command (now from streaming cache)
+export const fetchLogsViaIPC = async (
+  logLevel: LogLevel = "info",
+): Promise<ILogItem[]> => {
+  try {
+    const level = logLevel === "all" ? undefined : logLevel;
+    const response = await getClashLogs(level);
+
+    // The response should be in the format expected by the frontend
+    // Transform the logs to match the expected format
+    if (Array.isArray(response)) {
+      return response.map((log: any) => ({
+        ...log,
+        time: log.time || dayjs().format("HH:mm:ss"),
+      }));
+    }
+
+    return [];
+  } catch (error) {
+    console.error("[IPC-LogService] Failed to fetch logs:", error);
+    return [];
+  }
+};
+
+// Clear logs
+export const clearLogs = async () => {
+  try {
+    await clearLogsCmd();
+    console.log("[IPC-LogService] Logs cleared");
+  } catch (error) {
+    console.error("[IPC-LogService] Failed to clear logs:", error);
+  }
+};