diff --git a/agent/src/main.rs b/agent/src/main.rs
index 28be00b..7cdad6e 100644
--- a/agent/src/main.rs
+++ b/agent/src/main.rs
@@ -300,6 +300,7 @@ impl PublicIpProbe {
             let mut state = state.lock().unwrap();
             state.v4.observe(v4, observed_at);
             state.v6.observe(v6, observed_at);
+            drop(state);
             probing.store(false, Ordering::SeqCst);
         });
     }
@@ -753,8 +754,10 @@ fn os_name() -> String {
     text("/etc/os-release")
         .lines()
         .find_map(|line| line.strip_prefix("PRETTY_NAME="))
-        .map(|value| value.trim_matches('"').to_string())
-        .unwrap_or_else(|| command("uname", &["-s"]))
+        .map_or_else(
+            || command("uname", &["-s"]),
+            |value| value.trim_matches('"').to_string(),
+        )
 }
 
 #[cfg(target_os = "linux")]
@@ -1143,7 +1146,7 @@ fn sysfs_gpu_names() -> Vec<String> {
         return Vec::new();
     };
     entries
-        .filter_map(|entry| entry.ok())
+        .filter_map(std::result::Result::ok)
         .filter(|entry| {
             let name = entry.file_name();
             let name = name.to_string_lossy();
@@ -1208,10 +1211,7 @@ fn parse_pciconf_gpu_names(output: &str) -> Vec<String> {
     let mut block = Vec::new();
     for line in output.lines() {
         if !line.is_empty()
-            && !line
-                .chars()
-                .next()
-                .is_some_and(|character| character.is_whitespace())
+            && !line.chars().next().is_some_and(char::is_whitespace)
             && !block.is_empty()
         {
             if let Some(name) = block_name(&block) {
@@ -1345,9 +1345,7 @@ impl Collector {
     fn refresh_basic(&mut self) {
         let gpus = gpu_info();
         self.basic = BasicMetrics {
-            cpu_cores: thread::available_parallelism()
-                .map(|value| value.get() as i64)
-                .unwrap_or(1),
+            cpu_cores: thread::available_parallelism().map_or(1, |value| value.get() as i64),
             cpu_model: cpu_model(),
             os: os_name(),
             kernel: command("uname", &["-r"]),
@@ -1365,19 +1363,17 @@ impl Collector {
     }
 
     fn refresh_slow(&mut self) {
-        let processes = fs::read_dir("/proc")
-            .map(|items| {
-                items
-                    .filter_map(|item| item.ok())
-                    .filter(|item| {
-                        item.file_name()
-                            .to_string_lossy()
-                            .chars()
-                            .all(|ch| ch.is_ascii_digit())
-                    })
-                    .count() as i64
-            })
-            .unwrap_or(0);
+        let processes = fs::read_dir("/proc").map_or(0, |items| {
+            items
+                .filter_map(std::result::Result::ok)
+                .filter(|item| {
+                    item.file_name()
+                        .to_string_lossy()
+                        .chars()
+                        .all(|ch| ch.is_ascii_digit())
+                })
+                .count() as i64
+        });
         self.slow = SlowMetrics {
             disks: disk_usage(),
             processes,
@@ -1891,7 +1887,7 @@ fn receive_remote_output(
     }
 }
 
-fn remote_result_text(stdout: CapturedOutput, stderr: CapturedOutput) -> String {
+fn remote_result_text(stdout: &CapturedOutput, stderr: &CapturedOutput) -> String {
     let truncated = stdout.truncated || stderr.truncated;
     let stdout = String::from_utf8_lossy(&stdout.bytes);
     let stderr = String::from_utf8_lossy(&stderr.bytes);
@@ -1989,7 +1985,7 @@ fn execute_remote_task_with_timeout(
             terminate_remote_process_tree(&mut child);
             let stdout = receive_remote_output(&stdout, &mut child);
             let stderr = receive_remote_output(&stderr, &mut child);
-            let output = remote_result_text(stdout, stderr);
+            let output = remote_result_text(&stdout, &stderr);
             return TaskResultMessage {
                 message_type: "task_result".to_string(),
                 task_id,
@@ -2005,7 +2001,7 @@ fn execute_remote_task_with_timeout(
     };
     let stdout = receive_remote_output(&stdout, &mut child);
     let stderr = receive_remote_output(&stderr, &mut child);
-    let output = remote_result_text(stdout, stderr);
+    let output = remote_result_text(&stdout, &stderr);
 
     let Some(status) = status else {
         let timeout_seconds = timeout.as_secs().max(1);
@@ -2279,8 +2275,7 @@ fn live_sender_loop(endpoint: &str, token: &str, worker: LiveSenderWorker) {
     let mut socket: Option<LiveSocket> = None;
     let mut wss_interval = configured_interval
         .lock()
-        .map(|interval| *interval)
-        .unwrap_or(Duration::from_secs(1));
+        .map_or(Duration::from_secs(1), |interval| *interval);
     let mut accepted_through = persisted_through.load(Ordering::Acquire);
     let mut next_send_at = Instant::now();
     let mut next_probe_at = Instant::now();
@@ -2326,9 +2321,8 @@ fn live_sender_loop(endpoint: &str, token: &str, worker: LiveSenderWorker) {
         }
 
         let (queue_lock, ready) = &*pending;
-        let mut queue = match queue_lock.lock() {
-            Ok(queue) => queue,
-            Err(_) => return,
+        let Ok(mut queue) = queue_lock.lock() else {
+            return;
         };
         let batch = loop {
             let now = Instant::now();
@@ -2684,7 +2678,8 @@ fn rewrite_pending_spool(path: &Path, samples: &[Report]) -> Result<()> {
 }
 
 fn normalized_version(value: &str) -> &str {
-    value.trim().strip_prefix('v').unwrap_or(value.trim())
+    let value = value.trim();
+    value.strip_prefix('v').unwrap_or(value)
 }
 
 fn version_triplet(value: &str) -> Option<(u64, u64, u64)> {
@@ -3343,11 +3338,11 @@ mod tests {
     #[test]
     fn remote_command_output_is_bounded() {
         let result = remote_result_text(
-            CapturedOutput {
+            &CapturedOutput {
                 bytes: vec![b'x'; REMOTE_RESULT_OUTPUT_BYTES + 100],
                 truncated: true,
             },
-            CapturedOutput::default(),
+            &CapturedOutput::default(),
         );
         assert!(result.len() < REMOTE_RESULT_OUTPUT_BYTES + 64);
         assert!(result.ends_with("[输出已截断]"));
diff --git a/backend/migrations/postgres/01_initial.sql b/backend/migrations/postgres/01_initial.sql
index c9ea140..3e1bbcf 100644
--- a/backend/migrations/postgres/01_initial.sql
+++ b/backend/migrations/postgres/01_initial.sql
@@ -98,7 +98,7 @@ CREATE TABLE remote_tasks (
   id TEXT PRIMARY KEY,
   server_id TEXT NOT NULL REFERENCES servers(id) ON DELETE CASCADE,
   command TEXT NOT NULL,
-  status TEXT NOT NULL DEFAULT 'pending' CHECK(status IN ('pending', 'sent', 'running', 'success', 'failed')),
+  status TEXT NOT NULL DEFAULT 'pending' CHECK(status IN ('pending', 'sent', 'success', 'failed')),
   requested_by TEXT NOT NULL,
   requested_at BIGINT NOT NULL,
   started_at BIGINT,
diff --git a/backend/migrations/sqlite/01_initial.sql b/backend/migrations/sqlite/01_initial.sql
index 621e43b..9611443 100644
--- a/backend/migrations/sqlite/01_initial.sql
+++ b/backend/migrations/sqlite/01_initial.sql
@@ -100,7 +100,7 @@ CREATE TABLE remote_tasks (
   id TEXT PRIMARY KEY,
   server_id TEXT NOT NULL REFERENCES servers(id) ON DELETE CASCADE,
   command TEXT NOT NULL,
-  status TEXT NOT NULL DEFAULT 'pending' CHECK(status IN ('pending', 'sent', 'running', 'success', 'failed')),
+  status TEXT NOT NULL DEFAULT 'pending' CHECK(status IN ('pending', 'sent', 'success', 'failed')),
   requested_by TEXT NOT NULL,
   requested_at INTEGER NOT NULL,
   started_at INTEGER,
diff --git a/backend/src/backup.rs b/backend/src/backup.rs
index efbfcef..d6106e6 100644
--- a/backend/src/backup.rs
+++ b/backend/src/backup.rs
@@ -168,20 +168,16 @@ fn row_values(row: &AnyRow, columns: &[BackupColumn]) -> Result<Vec<Value>> {
             Ok(match column.kind {
                 BackupKind::Bool => row
                     .try_get::<Option<bool>, _>(index)?
-                    .map(Value::Bool)
-                    .unwrap_or(Value::Null),
+                    .map_or(Value::Null, Value::Bool),
                 BackupKind::SmallInt => row
                     .try_get::<Option<i16>, _>(index)?
-                    .map(|value| Value::Number(i64::from(value).into()))
-                    .unwrap_or(Value::Null),
+                    .map_or(Value::Null, |value| Value::Number(i64::from(value).into())),
                 BackupKind::Integer => row
                     .try_get::<Option<i32>, _>(index)?
-                    .map(|value| Value::Number(i64::from(value).into()))
-                    .unwrap_or(Value::Null),
+                    .map_or(Value::Null, |value| Value::Number(i64::from(value).into())),
                 BackupKind::BigInt => row
                     .try_get::<Option<i64>, _>(index)?
-                    .map(|value| Value::Number(value.into()))
-                    .unwrap_or(Value::Null),
+                    .map_or(Value::Null, |value| Value::Number(value.into())),
                 BackupKind::Real => match row.try_get::<Option<f32>, _>(index)? {
                     Some(value) => finite_json_number(f64::from(value))?,
                     None => Value::Null,
@@ -192,12 +188,10 @@ fn row_values(row: &AnyRow, columns: &[BackupColumn]) -> Result<Vec<Value>> {
                 },
                 BackupKind::Text => row
                     .try_get::<Option<String>, _>(index)?
-                    .map(Value::String)
-                    .unwrap_or(Value::Null),
+                    .map_or(Value::Null, Value::String),
                 BackupKind::Blob => row
                     .try_get::<Option<Vec<u8>>, _>(index)?
-                    .map(|value| Value::String(hex::encode(value)))
-                    .unwrap_or(Value::Null),
+                    .map_or(Value::Null, |value| Value::String(hex::encode(value))),
             })
         })
         .collect()
@@ -518,7 +512,7 @@ pub async fn restore_archive(db: &Database, archive: &[u8]) -> Result<usize> {
     sqlx::query(db.sql(
         "UPDATE remote_tasks SET status='failed', completed_at=?, \
          result=CASE WHEN result='' THEN '数据库恢复后已取消未完成任务' ELSE result END \
-         WHERE status IN ('pending','sent','running')",
+         WHERE status IN ('pending','sent')",
     ))
     .bind(crate::db::now())
     .execute(&mut *transaction)
diff --git a/backend/src/config.rs b/backend/src/config.rs
index 4d00916..bd5d9a3 100644
--- a/backend/src/config.rs
+++ b/backend/src/config.rs
@@ -10,7 +10,7 @@ pub const VERSION: &str = match option_env!("NODEFLARE_VERSION") {
 };
 
 #[derive(Debug, Parser)]
-#[command(version = VERSION, about = "NodeFlare standalone monitoring server")]
+#[command(version = VERSION, about = "NodeFlare monitoring server")]
 pub struct Args {
     /// Path to the TOML configuration file.
     #[arg(short, long, default_value = "/etc/nodeflare/config.toml")]
@@ -81,7 +81,7 @@ impl Config {
     pub fn load(path: &Path) -> Result<Self> {
         let content = std::fs::read_to_string(path)
             .with_context(|| format!("failed to read configuration {}", path.display()))?;
-        let mut config: Config = toml::from_str(&content)
+        let mut config: Self = toml::from_str(&content)
             .with_context(|| format!("failed to parse configuration {}", path.display()))?;
         let base = path
             .parent()
diff --git a/backend/src/db/mod.rs b/backend/src/db/mod.rs
index 7b5a9f7..5f68056 100644
--- a/backend/src/db/mod.rs
+++ b/backend/src/db/mod.rs
@@ -359,7 +359,7 @@ pub async fn initialize(pool: &Database, config: &Config) -> Result<()> {
         sqlx::query("DELETE FROM settings WHERE key LIKE 'session_%'")
             .execute(&mut *transaction)
             .await?;
-        tracing::info!(timestamp = now, "initialized standalone password scheme");
+        tracing::info!(timestamp = now, "initialized password scheme");
     }
     transaction.commit().await?;
     Ok(())
diff --git a/backend/src/db/queries.rs b/backend/src/db/queries.rs
index 5752d68..37fe687 100644
--- a/backend/src/db/queries.rs
+++ b/backend/src/db/queries.rs
@@ -570,7 +570,7 @@ async fn load_traffic_state(
         })
     })
     .transpose()
-    .map(|state| state.unwrap_or_default())
+    .map(Option::unwrap_or_default)
     .map_err(Into::into)
 }
 
@@ -870,7 +870,7 @@ pub async fn cleanup_database(db: &Database, retention_days: i64) -> Result<()>
     sqlx::query(db.sql(
         "UPDATE remote_tasks SET status='failed', completed_at=?, \
          result=CASE WHEN result='' THEN '任务等待超过 24 小时，已自动取消' ELSE result END \
-         WHERE status IN ('pending','sent','running') AND requested_at<?",
+         WHERE status IN ('pending','sent') AND requested_at<?",
     ))
     .bind(current)
     .bind(active_task_cutoff)
@@ -1530,7 +1530,8 @@ pub async fn remote_task(db: &Database, id: &str) -> Result<Option<RemoteTaskInf
     .bind(id)
     .fetch_optional(db.pool())
     .await?;
-    row.map(remote_task_from_row)
+    row.as_ref()
+        .map(remote_task_from_row)
         .transpose()
         .map_err(Into::into)
 }
@@ -1558,14 +1559,14 @@ pub async fn pending_remote_tasks(db: &Database, server_id: &str) -> Result<Vec<
     .fetch_all(&mut *transaction)
     .await?;
     transaction.commit().await?;
-    rows.into_iter()
+    rows.iter()
         .map(remote_task_from_row)
         .collect::<std::result::Result<Vec<_>, _>>()
         .map_err(Into::into)
 }
 
 fn remote_task_from_row(
-    row: sqlx::any::AnyRow,
+    row: &sqlx::any::AnyRow,
 ) -> std::result::Result<RemoteTaskInfo, sqlx::Error> {
     Ok(RemoteTaskInfo {
         id: row.try_get("id")?,
@@ -1604,7 +1605,7 @@ pub async fn update_remote_task_result(
 ) -> Result<bool> {
     let result = sqlx::query(db.sql(
         "UPDATE remote_tasks SET status=?, result=?, exit_code=?, completed_at=? \
-         WHERE id=? AND server_id=? AND status IN ('pending','sent','running')",
+         WHERE id=? AND server_id=? AND status IN ('pending','sent')",
     ))
     .bind(status)
     .bind(result)
diff --git a/backend/src/exchange.rs b/backend/src/exchange.rs
index 0ead939..ffcdc9b 100644
--- a/backend/src/exchange.rs
+++ b/backend/src/exchange.rs
@@ -75,7 +75,6 @@ async fn fetch_json(client: &reqwest::Client, url: &str) -> Result<Value> {
     let response = client
         .get(url)
         .header("Accept", "application/json")
-        .header("User-Agent", "NodeFlare-Standalone")
         .timeout(Duration::from_secs(8))
         .send()
         .await?
diff --git a/backend/src/main.rs b/backend/src/main.rs
index b9d21a3..125d790 100644
--- a/backend/src/main.rs
+++ b/backend/src/main.rs
@@ -4,6 +4,7 @@ mod config;
 mod db;
 mod exchange;
 mod middleware;
+mod mime;
 mod models;
 mod notify;
 mod routes;
@@ -64,7 +65,8 @@ impl AppState {
     }
 
     pub async fn disconnect_agent(&self, server_id: &str) {
-        if let Some(connection) = self.agents.write().await.remove(server_id) {
+        let connection = self.agents.write().await.remove(server_id);
+        if let Some(connection) = connection {
             let _ = connection.sender.try_send(websocket::AgentCommand::Close);
         }
     }
@@ -136,7 +138,7 @@ async fn main() -> Result<()> {
     }
 
     let http = reqwest::Client::builder()
-        .user_agent("NodeFlare-Standalone")
+        .user_agent(format!("NodeFlare/{}", config::VERSION))
         .connect_timeout(std::time::Duration::from_secs(5))
         .build()?;
     let (dashboard_tx, _) = broadcast::channel(2048);
diff --git a/backend/src/mime.rs b/backend/src/mime.rs
new file mode 100644
index 0000000..46eb496
--- /dev/null
+++ b/backend/src/mime.rs
@@ -0,0 +1,27 @@
+use std::path::Path;
+
+pub fn content_type(path: &Path) -> &'static str {
+    match path
+        .extension()
+        .and_then(|value| value.to_str())
+        .unwrap_or("")
+    {
+        "html" => "text/html; charset=utf-8",
+        "js" | "mjs" => "application/javascript; charset=utf-8",
+        "css" => "text/css; charset=utf-8",
+        "json" | "map" => "application/json; charset=utf-8",
+        "svg" => "image/svg+xml",
+        "png" => "image/png",
+        "jpg" | "jpeg" => "image/jpeg",
+        "webp" => "image/webp",
+        "gif" => "image/gif",
+        "ico" => "image/x-icon",
+        "woff" => "font/woff",
+        "woff2" => "font/woff2",
+        "ttf" => "font/ttf",
+        "wasm" => "application/wasm",
+        "sh" => "text/x-shellscript; charset=utf-8",
+        "ps1" => "text/plain; charset=utf-8",
+        _ => "application/octet-stream",
+    }
+}
diff --git a/backend/src/routes/admin.rs b/backend/src/routes/admin.rs
index 3f189d7..f90c4a6 100644
--- a/backend/src/routes/admin.rs
+++ b/backend/src/routes/admin.rs
@@ -161,8 +161,7 @@ pub async fn settings_patch(
     let next_username = input
         .admin_username
         .as_deref()
-        .map(str::trim)
-        .unwrap_or(&current.admin_username)
+        .map_or(current.admin_username.as_str(), str::trim)
         .to_string();
     let username_changed = next_username != user.username;
     if !username_changed {
diff --git a/backend/src/routes/auth.rs b/backend/src/routes/auth.rs
index f5aabb6..16600d7 100644
--- a/backend/src/routes/auth.rs
+++ b/backend/src/routes/auth.rs
@@ -294,14 +294,16 @@ pub(crate) fn session_device(headers: &HeaderMap, peer: SocketAddr) -> crate::db
         .and_then(|value| value.to_str().ok())
         .map(str::trim)
         .filter(|value| !value.is_empty())
-        .map(|value| {
-            value
-                .chars()
-                .filter(|character| !character.is_control())
-                .take(512)
-                .collect()
-        })
-        .unwrap_or_else(|| "未知客户端".to_string());
+        .map_or_else(
+            || "未知客户端".to_string(),
+            |value| {
+                value
+                    .chars()
+                    .filter(|character| !character.is_control())
+                    .take(512)
+                    .collect()
+            },
+        );
     crate::db::SessionDevice {
         ip_address,
         user_agent,
diff --git a/backend/src/routes/site.rs b/backend/src/routes/site.rs
index 2dd1225..caf2d98 100644
--- a/backend/src/routes/site.rs
+++ b/backend/src/routes/site.rs
@@ -44,14 +44,10 @@ pub async fn handle(State(state): State<Arc<AppState>>, OriginalUri(uri): Origin
             Ok(settings) => settings,
             Err(error) => return ApiResponse::internal(error).into_response(),
         };
-        let base = match crate::db::queries::theme_resolved_url(
-            &state.db,
-            &settings.active_theme_id,
-        )
-        .await
-        {
-            Ok(Some(base)) => base,
-            _ => return StatusCode::NOT_FOUND.into_response(),
+        let Ok(Some(base)) =
+            crate::db::queries::theme_resolved_url(&state.db, &settings.active_theme_id).await
+        else {
+            return StatusCode::NOT_FOUND.into_response();
         };
         return theme_file(&state, &base, relative, "/__theme-active").await;
     }
@@ -97,7 +93,7 @@ async fn local_file(root: &Path, relative: &str, cache: bool) -> Response {
         return StatusCode::NOT_FOUND.into_response();
     };
     match tokio::fs::read(&path).await {
-        Ok(body) => response(body, content_type(&path), cache),
+        Ok(body) => response(body, crate::mime::content_type(&path), cache),
         Err(_) => StatusCode::NOT_FOUND.into_response(),
     }
 }
@@ -149,26 +145,3 @@ fn response(body: Vec<u8>, content_type: &str, cache: bool) -> Response {
     }
     response
 }
-
-fn content_type(path: &Path) -> &'static str {
-    match path
-        .extension()
-        .and_then(|value| value.to_str())
-        .unwrap_or("")
-    {
-        "html" => "text/html; charset=utf-8",
-        "js" | "mjs" => "application/javascript; charset=utf-8",
-        "css" => "text/css; charset=utf-8",
-        "json" => "application/json; charset=utf-8",
-        "svg" => "image/svg+xml",
-        "png" => "image/png",
-        "jpg" | "jpeg" => "image/jpeg",
-        "webp" => "image/webp",
-        "ico" => "image/x-icon",
-        "woff2" => "font/woff2",
-        "wasm" => "application/wasm",
-        "sh" => "text/x-shellscript; charset=utf-8",
-        "ps1" => "text/plain; charset=utf-8",
-        _ => "application/octet-stream",
-    }
-}
diff --git a/backend/src/theme.rs b/backend/src/theme.rs
index 69e29e9..561919e 100644
--- a/backend/src/theme.rs
+++ b/backend/src/theme.rs
@@ -141,7 +141,7 @@ fn validate_release_asset_url(value: &str, owner: &str, repository: &str) -> Res
     let parsed = Url::parse(value).context("Release ZIP 下载地址无效")?;
     let parts = parsed
         .path_segments()
-        .map(|parts| parts.collect::<Vec<_>>())
+        .map(Iterator::collect::<Vec<_>>)
         .unwrap_or_default();
     if parsed.scheme() != "https"
         || parsed.host_str() != Some("github.com")
@@ -227,7 +227,7 @@ pub async fn fetch_theme_path(
     };
     let root = local_root(theme_dir, base)?;
     let body = read_local(&root, target, limit).await?;
-    let content_type = content_type(Path::new(target)).to_string();
+    let content_type = crate::mime::content_type(Path::new(target)).to_string();
     if target == "index.html" {
         let html = String::from_utf8(body)?;
         return Ok((rewrite_index(&html, prefix).into_bytes(), content_type));
@@ -276,7 +276,8 @@ fn empty_settings_schema() -> Value {
 }
 
 fn sanitize_version(value: &str) -> Option<String> {
-    let version = value.trim().strip_prefix('v').unwrap_or(value.trim());
+    let value = value.trim();
+    let version = value.strip_prefix('v').unwrap_or(value);
     (!version.is_empty()
         && version.len() <= 40
         && version
@@ -334,31 +335,6 @@ async fn read_local_optional(root: &Path, relative: &str, limit: usize) -> Resul
     Ok(Some(body))
 }
 
-fn content_type(path: &Path) -> &'static str {
-    match path
-        .extension()
-        .and_then(|value| value.to_str())
-        .unwrap_or("")
-    {
-        "html" => "text/html; charset=utf-8",
-        "js" | "mjs" => "application/javascript; charset=utf-8",
-        "css" => "text/css; charset=utf-8",
-        "json" => "application/json; charset=utf-8",
-        "svg" => "image/svg+xml",
-        "png" => "image/png",
-        "jpg" | "jpeg" => "image/jpeg",
-        "webp" => "image/webp",
-        "gif" => "image/gif",
-        "ico" => "image/x-icon",
-        "woff" => "font/woff",
-        "woff2" => "font/woff2",
-        "ttf" => "font/ttf",
-        "wasm" => "application/wasm",
-        "map" => "application/json; charset=utf-8",
-        _ => "application/octet-stream",
-    }
-}
-
 fn install_archive_blocking(theme_dir: &Path, id: &str, archive: Vec<u8>) -> Result<()> {
     fs::create_dir_all(theme_dir)
         .with_context(|| format!("无法创建主题目录 {}", theme_dir.display()))?;
diff --git a/backend/src/websocket/agent.rs b/backend/src/websocket/agent.rs
index 0f7a9f3..859e326 100644
--- a/backend/src/websocket/agent.rs
+++ b/backend/src/websocket/agent.rs
@@ -180,12 +180,14 @@ async fn run(
         }
     }
     writer.abort();
-    let mut agents = state.agents.write().await;
-    if agents
-        .get(&identity.server_id)
-        .is_some_and(|connection| connection.connection_id == connection_id)
     {
-        agents.remove(&identity.server_id);
+        let mut agents = state.agents.write().await;
+        if agents
+            .get(&identity.server_id)
+            .is_some_and(|connection| connection.connection_id == connection_id)
+        {
+            agents.remove(&identity.server_id);
+        }
     }
     tracing::info!(server_id = %identity.server_id, "Agent disconnected");
 }
diff --git a/backend/src/websocket/dashboard.rs b/backend/src/websocket/dashboard.rs
index d4da35c..77abe55 100644
--- a/backend/src/websocket/dashboard.rs
+++ b/backend/src/websocket/dashboard.rs
@@ -55,8 +55,7 @@ async fn run(socket: WebSocket, state: Arc<AppState>, server_id: Option<String>)
                         break;
                     }
                 }
-                Ok(_) => {}
-                Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => {}
+                Ok(_) | Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => {}
                 Err(tokio::sync::broadcast::error::RecvError::Closed) => break,
             },
             incoming = receiver.next() => match incoming {
diff --git a/frontend/src/AppProvider.tsx b/frontend/src/AppProvider.tsx
index 5877890..1d267f3 100644
--- a/frontend/src/AppProvider.tsx
+++ b/frontend/src/AppProvider.tsx
@@ -10,6 +10,7 @@ import {
   type PlaybackBuffer,
 } from "./live";
 import { ui } from "./locale";
+import { useFavicon, useStoredAppearance, useSystemDark } from "./hooks/useBrowserAppearance";
 import { resolveBackground, themeToggle } from "./theme";
 import {
   BOOTSTRAP_POLL_INTERVAL_MS,
@@ -82,11 +83,8 @@ export function AppProvider({ children }: { children: ReactNode }) {
   const [error, setError] = useState("");
   const [access, setAccess] = useState<Access>("ok");
   const [selectedId, setSelectedId] = useState<string | null>(routeServerId);
-  const [appearance, setAppearance] = useState<"light" | "dark" | null>(() => {
-    const stored = localStorage.getItem("nodeflare-theme");
-    return stored === "light" || stored === "dark" ? stored : null;
-  });
-  const [systemDark, setSystemDark] = useState(() => matchMedia("(prefers-color-scheme: dark)").matches);
+  const [appearance, setAppearance] = useStoredAppearance("nodeflare-theme");
+  const systemDark = useSystemDark();
   const liveConnectedRef = useRef(false);
   const playbackRef = useRef<PlaybackBuffer>(new Map());
   const serversRef = useRef<Server[]>([]);
@@ -99,6 +97,7 @@ export function AppProvider({ children }: { children: ReactNode }) {
   const background = resolveBackground(config.background_url, dark);
   const blur = themeToggle(config, "enableBlur");
   const carrierLatency = config.show_latency && themeToggle(config, "showCarrierLatency", false);
+  useFavicon(config.logo_url);
 
   if (!reloadQueueRef.current) {
     reloadQueueRef.current = createRefreshQueue(async (quiet) => {
@@ -266,24 +265,6 @@ export function AppProvider({ children }: { children: ReactNode }) {
     document.documentElement.lang = config.locale;
   }, [blur, config.locale, dark]);
 
-  useEffect(() => {
-    let link = document.querySelector<HTMLLinkElement>('link[rel="icon"]');
-    if (!link) {
-      link = document.createElement("link");
-      link.rel = "icon";
-      document.head.append(link);
-    }
-    link.removeAttribute("type");
-    link.href = config.logo_url || "/logo.svg";
-  }, [config.logo_url]);
-
-  useEffect(() => {
-    const media = matchMedia("(prefers-color-scheme: dark)");
-    const update = () => setSystemDark(media.matches);
-    media.addEventListener("change", update);
-    return () => media.removeEventListener("change", update);
-  }, []);
-
   useEffect(() => {
     const onPop = () => setSelectedId(routeServerId());
     window.addEventListener("popstate", onPop);
@@ -317,7 +298,6 @@ export function AppProvider({ children }: { children: ReactNode }) {
     setAppearance((current) => {
       const resolved = current ?? (dark ? "dark" : "light");
       const next = resolved === "dark" ? "light" : "dark";
-      localStorage.setItem("nodeflare-theme", next);
       return next;
     });
   }, [dark]);
diff --git a/frontend/src/admin-main.tsx b/frontend/src/admin-main.tsx
index 4578d4c..557bfed 100644
--- a/frontend/src/admin-main.tsx
+++ b/frontend/src/admin-main.tsx
@@ -2,22 +2,17 @@ import { StrictMode, useEffect, useState } from "react";
 import { createRoot } from "react-dom/client";
 import { api } from "./api";
 import { AdminPanel } from "./components/AdminPanel";
+import { useFavicon, useStoredAppearance, useSystemDark } from "./hooks/useBrowserAppearance";
 import type { Config } from "./types";
 import "./styles/admin.css";
 
-const THEME_KEY = "nodeflare-admin-theme";
-
-function initialAppearance(): "light" | "dark" | null {
-  const stored = localStorage.getItem(THEME_KEY);
-  return stored === "light" || stored === "dark" ? stored : null;
-}
-
 function AdminApp() {
   const [config, setConfig] = useState<Config | null>(null);
   const [error, setError] = useState("");
-  const [appearance, setAppearance] = useState<"light" | "dark" | null>(initialAppearance);
-  const [systemDark, setSystemDark] = useState(() => matchMedia("(prefers-color-scheme: dark)").matches);
+  const [appearance, setAppearance] = useStoredAppearance("nodeflare-admin-theme");
+  const systemDark = useSystemDark();
   const dark = appearance ? appearance === "dark" : config?.default_theme === "system" || !config ? systemDark : config.default_theme === "dark";
+  useFavicon(config?.logo_url);
 
   async function loadConfig() {
     try {
@@ -34,31 +29,14 @@ function AdminApp() {
     document.documentElement.classList.toggle("dark", dark);
     document.documentElement.style.colorScheme = dark ? "dark" : "light";
   }, [dark]);
-  useEffect(() => {
-    const media = matchMedia("(prefers-color-scheme: dark)");
-    const update = () => setSystemDark(media.matches);
-    media.addEventListener("change", update);
-    return () => media.removeEventListener("change", update);
-  }, []);
   useEffect(() => {
     document.title = config ? `管理面板 · ${config.site_name}` : "管理面板";
   }, [config]);
-  useEffect(() => {
-    let link = document.querySelector<HTMLLinkElement>('link[rel="icon"]');
-    if (!link) {
-      link = document.createElement("link");
-      link.rel = "icon";
-      document.head.append(link);
-    }
-    link.removeAttribute("type");
-    link.href = config?.logo_url || "/logo.svg";
-  }, [config?.logo_url]);
 
   if (error) return <div className={`admin-loading ${dark ? "admin-dark" : ""}`}><span>{error}</span><button className="secondary-btn" onClick={() => void loadConfig()}>重试</button></div>;
   if (!config) return <div className={`admin-loading ${dark ? "admin-dark" : ""}`}>正在加载管理面板</div>;
   return <AdminPanel config={config} dark={dark} onToggleTheme={() => {
     const next = dark ? "light" : "dark";
-    localStorage.setItem(THEME_KEY, next);
     setAppearance(next);
   }} onChanged={() => void loadConfig()} />;
 }
diff --git a/frontend/src/format.ts b/frontend/src/format.ts
index a2df260..7495ea6 100644
--- a/frontend/src/format.ts
+++ b/frontend/src/format.ts
@@ -15,7 +15,7 @@ export interface FormattedBytes {
   unit: string;
 }
 
-export function formatBytesParts(value: number | null | undefined, decimals = 1): FormattedBytes {
+function formatBytesParts(value: number | null | undefined, decimals = 1): FormattedBytes {
   const size = Math.max(0, number(value));
   if (size === 0) return { value: "0", unit: "B" };
   const units = ["B", "KB", "MB", "GB", "TB", "PB"];
diff --git a/frontend/src/hooks/useBrowserAppearance.ts b/frontend/src/hooks/useBrowserAppearance.ts
new file mode 100644
index 0000000..755ebca
--- /dev/null
+++ b/frontend/src/hooks/useBrowserAppearance.ts
@@ -0,0 +1,44 @@
+import { useEffect, useState } from "react";
+
+type Appearance = "light" | "dark";
+
+export function useStoredAppearance(key: string) {
+  const [appearance, setAppearance] = useState<Appearance | null>(() => {
+    const stored = localStorage.getItem(key);
+    return stored === "light" || stored === "dark" ? stored : null;
+  });
+
+  useEffect(() => {
+    if (appearance) localStorage.setItem(key, appearance);
+  }, [appearance, key]);
+
+  return [appearance, setAppearance] as const;
+}
+
+export function useSystemDark() {
+  const [systemDark, setSystemDark] = useState(
+    () => matchMedia("(prefers-color-scheme: dark)").matches,
+  );
+
+  useEffect(() => {
+    const media = matchMedia("(prefers-color-scheme: dark)");
+    const update = () => setSystemDark(media.matches);
+    media.addEventListener("change", update);
+    return () => media.removeEventListener("change", update);
+  }, []);
+
+  return systemDark;
+}
+
+export function useFavicon(logoUrl: string | null | undefined) {
+  useEffect(() => {
+    let link = document.querySelector<HTMLLinkElement>('link[rel="icon"]');
+    if (!link) {
+      link = document.createElement("link");
+      link.rel = "icon";
+      document.head.append(link);
+    }
+    link.removeAttribute("type");
+    link.href = logoUrl || "/logo.svg";
+  }, [logoUrl]);
+}
diff --git a/frontend/src/latency.ts b/frontend/src/latency.ts
index 6dfe345..abfb781 100644
--- a/frontend/src/latency.ts
+++ b/frontend/src/latency.ts
@@ -2,7 +2,7 @@ import { clockLabel } from "./chart";
 import { ui, type UiLocale } from "./locale";
 import type { LatencySample } from "./types";
 
-export type LatencyTone = "good" | "fair" | "warning" | "poor" | "danger" | "empty";
+type LatencyTone = "good" | "fair" | "warning" | "poor" | "danger" | "empty";
 
 export interface LatencyBar {
   key: string;
@@ -31,7 +31,7 @@ export const CARRIER_SLOTS = [
 
 export type CarrierSlot = typeof CARRIER_SLOTS[number];
 
-export function latencyTone(value: number): LatencyTone {
+function latencyTone(value: number): LatencyTone {
   if (value <= 60) return "good";
   if (value <= 100) return "fair";
   if (value <= 160) return "warning";
@@ -39,7 +39,7 @@ export function latencyTone(value: number): LatencyTone {
   return "danger";
 }
 
-export function lossTone(value: number): LatencyTone {
+function lossTone(value: number): LatencyTone {
   if (value <= 1) return "good";
   if (value <= 3) return "fair";
   if (value <= 6) return "warning";
diff --git a/frontend/src/live.ts b/frontend/src/live.ts
index dc30d9e..3007e42 100644
--- a/frontend/src/live.ts
+++ b/frontend/src/live.ts
@@ -1,7 +1,7 @@
 import type { LatencySample, LiveLatencyResult, Server } from "./types";
 
 /** A single Agent report as replayed by the NodeFlare server. */
-export interface LiveSample {
+interface LiveSample {
   ts: number;
   data: Partial<Server> & { latency_results?: LiveLatencyResult[] };
 }
@@ -30,7 +30,7 @@ export interface BatchUpdate {
   reportAgeMs?: number;
 }
 
-export const MAX_PLAYBACK_SAMPLES_PER_SERVER = 600;
+const MAX_PLAYBACK_SAMPLES_PER_SERVER = 600;
 const MAX_LIVE_LATENCY_RESULTS = 4096;
 
 export function mergeLiveResults(
diff --git a/frontend/src/theme.ts b/frontend/src/theme.ts
index 24e434c..ca8d766 100644
--- a/frontend/src/theme.ts
+++ b/frontend/src/theme.ts
@@ -17,7 +17,7 @@ export function themeToggle(config: Config, key: string, fallback = true) {
   return typeof value === "boolean" ? value : fallback;
 }
 
-export function themeText(config: Config, key: string) {
+function themeText(config: Config, key: string) {
   const value = option(config, key);
   return typeof value === "string" ? value.trim() : "";
 }
diff --git a/scripts/build-frontend.sh b/scripts/build-frontend.sh
index 603d8ce..9fd48a5 100644
--- a/scripts/build-frontend.sh
+++ b/scripts/build-frontend.sh
@@ -10,7 +10,3 @@ cd "$root_dir"
 
 [ -d node_modules ] || bun install --frozen-lockfile
 bun run --cwd frontend build
-
-if build_key=$(sh scripts/build-key.sh frontend 2>/dev/null); then
-  printf '%s\n' "$build_key" > frontend/dist/.nodeflare-revision
-fi
diff --git a/scripts/build-key.sh b/scripts/build-key.sh
deleted file mode 100644
index 3f82ba2..0000000
--- a/scripts/build-key.sh
+++ /dev/null
@@ -1,25 +0,0 @@
-#!/bin/sh
-set -eu
-
-case "${1:-}" in
-  frontend)
-    paths="frontend package.json bun.lock scripts/build-frontend.sh scripts/build-key.sh scripts/resolve-version.sh"
-    ;;
-  backend)
-    paths="backend/Cargo.toml backend/Cargo.lock backend/src backend/migrations scripts/build-backend.sh scripts/build-key.sh scripts/resolve-version.sh"
-    ;;
-  *)
-    echo "usage: $0 frontend|backend" >&2
-    exit 2
-    ;;
-esac
-
-{
-  sh scripts/resolve-version.sh
-  git rev-parse HEAD
-  git diff --binary -- $paths
-  git ls-files --others --exclude-standard -- $paths | while IFS= read -r file; do
-    printf '%s ' "$file"
-    git hash-object "$file"
-  done
-} | cksum | awk '{ print $1 "-" $2 }'
diff --git a/start.sh b/start.sh
index 13c828b..abfac41 100755
--- a/start.sh
+++ b/start.sh
@@ -10,7 +10,7 @@ if [ -z "$config_path" ]; then
     config_path=/etc/nodeflare/config.toml
   elif [ -f backend/config.toml ]; then
     config_path=backend/config.toml
-    echo "正在使用兼容的本地配置 backend/config.toml"
+    echo "正在使用本地开发配置 backend/config.toml"
   else
     echo "未找到 /etc/nodeflare/config.toml" >&2
     echo "请先运行 sudo ./install.sh，安装时会询问管理员用户名和密码。" >&2