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-tauri/src/ipc/memory.rs

@@ -8,7 +8,7 @@ use tokio::{sync::RwLock, time::Duration};
 
 use crate::{
     logging,
-    utils::{dirs::ipc_path, logging::Type},
+    utils::{dirs::ipc_path, format::fmt_bytes, logging::Type},
 };
 
 #[derive(Debug, Clone, Deserialize, Serialize)]
@@ -101,16 +101,6 @@ impl MemoryMonitor {
     }
 }
 
-fn fmt_bytes(bytes: u64) -> String {
-    const UNITS: &[&str] = &["B", "KB", "MB", "GB"];
-    let (mut val, mut unit) = (bytes as f64, 0);
-    while val >= 1024.0 && unit < 3 {
-        val /= 1024.0;
-        unit += 1;
-    }
-    format!("{:.1}{}", val, UNITS[unit])
-}
-
 pub async fn get_current_memory() -> CurrentMemory {
     MemoryMonitor::global().current().await
 }