feat: add daemon log viewer to web UI

Co-authored-by: aider (gemini/gemini-2.5-pro-preview-05-06) <aider@aider.chat>

src/logger.rs

@@ -0,0 +1,52 @@
+use chrono::Local;
+use log::{LevelFilter, Log, Metadata, Record};
+use std::collections::VecDeque;
+use std::sync::{Arc, Mutex};
+
+const MAX_LOG_ENTRIES: usize = 100;
+
+struct RingBufferLogger {
+    buffer: Arc<Mutex<VecDeque<String>>>,
+}
+
+impl Log for RingBufferLogger {
+    fn enabled(&self, metadata: &Metadata) -> bool {
+        metadata.level() <= LevelFilter::Info
+    }
+
+    fn log(&self, record: &Record) {
+        if self.enabled(record.metadata()) {
+            let msg = format!(
+                "{} [{}] {}",
+                Local::now().format("%Y-%m-%d %H:%M:%S"),
+                record.level(),
+                record.args()
+            );
+
+            // Also print to stderr for console/daemon logging
+            eprintln!("{}", msg);
+
+            let mut buffer = self.buffer.lock().unwrap();
+            if buffer.len() == MAX_LOG_ENTRIES {
+                buffer.pop_front();
+            }
+            buffer.push_back(msg);
+        }
+    }
+
+    fn flush(&self) {}
+}
+
+pub fn setup_logger() -> Arc<Mutex<VecDeque<String>>> {
+    let buffer = Arc::new(Mutex::new(VecDeque::with_capacity(MAX_LOG_ENTRIES)));
+    let logger = RingBufferLogger {
+        buffer: buffer.clone(),
+    };
+
+    // We use `set_boxed_logger` to install our custom logger.
+    // The `log` crate will then route all log messages to it.
+    log::set_boxed_logger(Box::new(logger)).expect("Failed to set logger");
+    log::set_max_level(LevelFilter::Info);
+
+    buffer
+}