Consolidate ARP/mDNS modules under scanners::{arp,mdns}::{finder,scanner,status}

Group each discovery protocol's primitive (finder), orchestration loop
(scanner), and status state under one module tree instead of splitting
them between device_finders/ and crate-root *_scanner / *_scanner_status
files. Also includes incidental rustfmt fixes to a few pre-existing
long lines.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/src/db/devices.rs

@@ -208,7 +208,9 @@ pub fn seen(
     // device_type is only written when the stored value is empty, so a value chosen by the
     // user (via register) or previously deduced is never overwritten by a later sighting.
     if !vendor.is_empty() {
-        sql.push_str(", vendor=?, device_type=CASE WHEN device_type='' THEN ? ELSE device_type END");
+        sql.push_str(
+            ", vendor=?, device_type=CASE WHEN device_type='' THEN ? ELSE device_type END",
+        );
         params.push(vendor.into());
         params.push(device_type.into());
     }
@@ -377,8 +379,17 @@ mod tests {
         );
 
         // Filter by owner substring - "oh" matches "John" but not "Sarah"
-        let devices: Vec<Device> =
+        let devices: Vec<Device> = list_devices(
-            list_devices(None, None, None, Some("oh".to_string()), None, None, None, None).unwrap();
+            None,
+            None,
+            None,
+            Some("oh".to_string()),
+            None,
+            None,
+            None,
+            None,
+        )
+        .unwrap();
 
         assert!(
             devices.len() >= 1,
@@ -426,7 +437,8 @@ mod tests {
         tests_common::setup().await;
 
         // First page with 2 devices
-        let first_page = list_devices(None, None, None, None, None, None, Some(0), Some(2)).unwrap();
+        let first_page =
+            list_devices(None, None, None, None, None, None, Some(0), Some(2)).unwrap();
         assert_eq!(first_page.len(), 2, "First page should have 2 devices");
 
         // Second page with 2 devices, should have at least 1 (seed data has >= 3 devices)

backend/src/main.rs

@@ -2,16 +2,12 @@ use crate::settings::get_settings;
 use clap::Parser;
 use log::{LevelFilter, info};
 
-mod arp_scanner;
-mod arp_scanner_status;
 mod data;
 mod db;
-mod device_finders;
 mod events;
-mod mdns_scanner;
-mod mdns_scanner_status;
 mod model;
 mod retention;
+mod scanners;
 mod settings;
 mod utils;
 mod web_server;
@@ -61,13 +57,13 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     db::init_db().await?;
 
     // Initialize scanner status tracking
-    arp_scanner_status::init();
+    scanners::arp::status::init();
-    mdns_scanner_status::init();
+    scanners::mdns::status::init();
 
     // Start the device scanners, web server, and retention cleaner in parallel
     tokio::join!(
-        arp_scanner::scan(),
+        scanners::arp::scanner::scan(),
-        mdns_scanner::listen(),
+        scanners::mdns::scanner::listen(),
         web_server::serve(),
         retention::run()
     )

backend/src/scanners/arp.rs

@@ -0,0 +1,4 @@
+pub mod finder;
+mod packet_send_receive;
+pub mod scanner;
+pub mod status;

backend/src/scanners/arp/finder.rs

@@ -1,14 +1,12 @@
-mod packet_send_receive;
+use super::packet_send_receive::{listen_for_packets, send_packet};
-
+use crate::model::devices::Device;
-use crate::device_finders::error::{
+use crate::scanners::error::{
     DataChannelError, InvalidDeviceError, NoIPAddressError, NoMACAddressError,
 };
-use crate::model::devices::Device;
 use crate::settings::get_settings;
 use crate::utils::network::select_interface;
 use duration_string::DurationString;
 use log::{debug, error, info, warn};
-use packet_send_receive::{listen_for_packets, send_packet};
 use pnet::{
     datalink::{self, Channel, NetworkInterface},
     ipnetwork::IpNetwork,

backend/src/scanners/arp/scanner.rs

@@ -1,6 +1,6 @@
-use crate::arp_scanner_status;
+use super::finder;
+use super::status as arp_scanner_status;
 use crate::db;
-use crate::device_finders;
 use crate::events;
 use crate::settings::get_settings;
 use chrono::Utc;
@@ -12,8 +12,7 @@ pub async fn scan() -> Result<(), Box<dyn std::error::Error>> {
         arp_scanner_status::set_running();
 
         // Find online devices via ARP
-        let devices =
+        let devices = finder::find(get_settings().networking.interface.clone()).await?;
-            device_finders::arp::find(get_settings().networking.interface.clone()).await?;
 
         info!("Done with ARP probes");
         info!("Found {} online devices", devices.len());

backend/src/scanners/mdns.rs

@@ -0,0 +1,3 @@
+pub mod finder;
+pub mod scanner;
+pub mod status;

backend/src/scanners/mdns/finder.rs

@@ -67,7 +67,12 @@ pub fn parse_announcement(buf: &[u8]) -> Announcement {
         }
     };
 
-    let records = || packet.answers.iter().chain(packet.additional_records.iter());
+    let records = || {
+        packet
+            .answers
+            .iter()
+            .chain(packet.additional_records.iter())
+    };
 
     let hostnames = records()
         .filter(|record| matches!(record.rdata, RData::A(_)))

backend/src/scanners/mdns/scanner.rs

@@ -4,14 +4,14 @@ use std::time::Duration;
 use chrono::Local;
 use log::{debug, error, info, warn};
 
-use crate::db;
+use super::finder as mdns;
-use crate::device_finders::mdns;
+use super::status as mdns_scanner_status;
-use crate::events;
 use crate::data::mac_vendor_finder;
-use crate::mdns_scanner_status;
+use crate::data::vendor_device_type_finder;
+use crate::db;
+use crate::events;
 use crate::model::devices::Device;
 use crate::settings::get_settings;
-use crate::data::vendor_device_type_finder;
 
 /// Passively listen for mDNS/Bonjour announcements and feed discovered devices into the same
 /// pipeline used by the ARP scanner (devices table + events + notifications).
@@ -62,7 +62,8 @@ async fn process_announcement(
     interface: Option<String>,
     probe_timeout: Duration,
 ) {
-    let mac = match crate::utils::network::resolve_mac_address(src_ip, interface, probe_timeout).await {
+    let mac =
+        match crate::utils::network::resolve_mac_address(src_ip, interface, probe_timeout).await {
             Some(mac) => mac.to_string(),
             None => {
                 debug!("Could not resolve MAC for mDNS device {src_ip} ({hostname}); skipping");

backend/src/web_server/arp_scanner.rs

@@ -4,7 +4,7 @@ use log::error;
 use serde::Serialize;
 use utoipa::ToSchema;
 
-use crate::arp_scanner_status;
+use crate::scanners::arp::status as arp_scanner_status;
 
 #[derive(Serialize, ToSchema)]
 pub struct ArpScannerStatusResponse {

backend/src/web_server/devices.rs

@@ -176,7 +176,12 @@ pub async fn update(
         );
     }
 
-    match db::devices::update(mac_address, payload.owner, payload.device_type, payload.vendor) {
+    match db::devices::update(
+        mac_address,
+        payload.owner,
+        payload.device_type,
+        payload.vendor,
+    ) {
         Ok(_) => (axum::http::StatusCode::OK, "Device updated"),
         Err(err) => {
             error!("Error updating device in the database: {}", err);

backend/src/web_server/mdns_scanner.rs

@@ -4,7 +4,7 @@ use log::error;
 use serde::Serialize;
 use utoipa::ToSchema;
 
-use crate::mdns_scanner_status;
+use crate::scanners::mdns::status as mdns_scanner_status;
 
 #[derive(Serialize, ToSchema)]
 pub struct MdnsScannerStatusResponse {