refactor: centralize BYTES_PER_MB and tidy peer IP parsing

- Add pub const BYTES_PER_MB to ui/utils.rs and replace 7 uses of the
  bare 1_048_576.0 literal across the UI modules. Also pick up
  uninlined-format-args cleanup in the same file while we're here.
- Replace Vec<i32> IP-byte accumulator in Peer::new_from_message with a
  [u8; 4]; the .abs() calls on u8.into() were no-ops on always-positive
  values. Network byte order ([3].[2].[1].[0]) preserved; tests cover
  the wire format.

soulseek-rs-lib/src/peer/mod.rs

@@ -119,17 +119,13 @@ impl Peer {
         let username = message.read_string();
         let connection_type = message.read_string().parse().unwrap();
 
-        let mut ip: Vec<i32> = vec![];
-        for _ in 0..4 {
-            ip.push(message.read_int8().into());
-        }
-        let host: String = format!(
-            "{}.{}.{}.{}",
-            ip[3].abs(),
-            ip[2].abs(),
-            ip[1].abs(),
-            ip[0].abs()
-        );
+        let ip = [
+            message.read_int8(),
+            message.read_int8(),
+            message.read_int8(),
+            message.read_int8(),
+        ];
+        let host = format!("{}.{}.{}.{}", ip[3], ip[2], ip[1], ip[0]);
 
         let (port, token, privileged, unknown, obfuscated_port) = (
             message.read_int32(),

soulseek-rs/src/ui/download_selector.rs

@@ -1,6 +1,6 @@
 use crate::models::FileDisplayData;
 use crate::ui::{
-    HIGHLIGHT_SYMBOL, border_style, border_type, format_bytes,
+    BYTES_PER_MB, HIGHLIGHT_SYMBOL, border_style, border_type, format_bytes,
     format_shortcuts_styled, get_bitrate, get_spinner_char, header_style,
     highlight_style, primary_style, success_style, warning_style,
 };
@@ -379,7 +379,7 @@ impl FileSelector {
                 let is_selected = self.selected_indices.contains(&original_idx);
                 let checkbox = if is_selected { "[✓]" } else { "[ ]" };
 
-                let speed_mb = item.speed as f64 / 1_048_576.0;
+                let speed_mb = item.speed as f64 / BYTES_PER_MB;
                 let speed_str = if speed_mb > 0.0 {
                     format!("{:.1} MB/s", speed_mb)
                 } else {

soulseek-rs/src/ui/downloads.rs

@@ -1,9 +1,9 @@
 use crate::models::DownloadEntry;
 use crate::ui::{
-    COLOR_PRIMARY, HIGHLIGHT_SYMBOL, border_style, border_type, error_style,
-    format_bytes_progress, format_progress_bar, format_shortcuts_styled,
-    format_speed, header_style, highlight_style, inactive_style, info_style,
-    primary_style, warning_style,
+    BYTES_PER_MB, COLOR_PRIMARY, HIGHLIGHT_SYMBOL, border_style, border_type,
+    error_style, format_bytes_progress, format_progress_bar,
+    format_shortcuts_styled, format_speed, header_style, highlight_style,
+    inactive_style, info_style, primary_style, warning_style,
 };
 use color_eyre::Result;
 use ratatui::{
@@ -381,7 +381,7 @@ pub fn render_download_stats(
         })
         .map(|d| d.download.speed_bytes_per_sec())
         .sum();
-    let speed_mb = (total_speed / 1_048_576.0 * 100.0).round() / 100.0;
+    let speed_mb = (total_speed / BYTES_PER_MB * 100.0).round() / 100.0;
 
     let block = Block::default()
         .borders(Borders::ALL)

soulseek-rs/src/ui/panes/results_pane.rs

@@ -1,7 +1,7 @@
 use crate::models::FileDisplayData;
 use crate::ui::{
-    HIGHLIGHT_SYMBOL, border_style, border_type, format_bytes, header_style,
-    highlight_style,
+    BYTES_PER_MB, HIGHLIGHT_SYMBOL, border_style, border_type, format_bytes,
+    header_style, highlight_style,
 };
 use ratatui::{
     Frame,
@@ -96,7 +96,7 @@ No results. Select a search from the Searches pane [1]. Or start new search [s
 
             let speed_str = if file.speed > 0 {
                 let speed_mb =
-                    (file.speed as f64 / 1_048_576.0 * 100.0).round() / 100.0;
+                    (file.speed as f64 / BYTES_PER_MB * 100.0).round() / 100.0;
                 format!("{} MB/s", speed_mb)
             } else {
                 "-".to_string()

soulseek-rs/src/ui/utils.rs

@@ -5,28 +5,29 @@ use ratatui::{
 
 use crate::ui::COLOR_PRIMARY;
 
+pub const BYTES_PER_MB: f64 = 1_048_576.0;
+
 pub fn format_bytes(bytes: u64) -> String {
-    let mb = bytes as f64 / 1_048_576.0;
-    format!("{:.1} MB", mb)
+    let mb = bytes as f64 / BYTES_PER_MB;
+    format!("{mb:.1} MB")
 }
 
 pub fn format_bytes_progress(downloaded: u64, total: u64) -> Line<'static> {
-    let downloaded_mb = downloaded as f64 / 1_048_576.0;
-    let total_mb = total as f64 / 1_048_576.0;
+    let downloaded_mb = downloaded as f64 / BYTES_PER_MB;
+    let total_mb = total as f64 / BYTES_PER_MB;
 
-    let mut spans = vec![];
-    spans.push(Span::styled(
-        format!("{:.1}/{:.1}", downloaded_mb, total_mb),
-        Style::default().fg(COLOR_PRIMARY),
-    ));
-    spans.push(Span::raw(" MB"));
-
-    Line::from(spans)
+    Line::from(vec![
+        Span::styled(
+            format!("{downloaded_mb:.1}/{total_mb:.1}"),
+            Style::default().fg(COLOR_PRIMARY),
+        ),
+        Span::raw(" MB"),
+    ])
 }
 
 pub fn format_speed(speed_bytes_per_sec: f64) -> String {
-    let mb = speed_bytes_per_sec / 1_048_576.0;
-    format!("{:.1} MB/s", mb)
+    let mb = speed_bytes_per_sec / BYTES_PER_MB;
+    format!("{mb:.1} MB/s")
 }
 
 pub fn get_bitrate(
@@ -35,7 +36,6 @@ pub fn get_bitrate(
     attribs.get(&0).copied()
 }
 
-// Spinner animation chars
 const SPINNER_CHARS: [&str; 10] =
     ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"];