pull,ui,report: render the pull downloads as byte progress

The pull downloads reported through the plain count port only because
byte_progress landed on main after the branch was cut. PullView now
implements it with a byte-counter template in the transfer-style
family (same shape, {bytes}/{total_bytes} counters, human-formatted by
indicatif), downloads emit through it, and the trait doc lists the
event among the ones the pull flow emits — un-duplicating the merged
'message, progress and progress' sentence.

src/ui.rs

@@ -41,6 +41,17 @@ pub(crate) fn transfer_style() -> ProgressStyle {
         .progress_chars("=> ")
 }
 
+/// [`transfer_style`] with human-formatted byte counters, for the events
+/// reported through [`crate::report::BuildView::byte_progress`]
+pub(crate) fn byte_style() -> ProgressStyle {
+    ProgressStyle::default_bar()
+        .template(
+            "> {spinner:.blue} {prefix}\n      {msg} [{bar:40.cyan/blue}] {bytes}/{total_bytes} ({eta})",
+        )
+        .unwrap()
+        .progress_chars("=> ")
+}
+
 /// A standalone spinner for one-line waits outside a build view (the
 /// prune size pass): braille frames over the message behind the `> `
 /// prompt prefix, drawn only on terminals. Callers finish it with
@@ -142,6 +153,17 @@ impl crate::report::BuildView for PullView {
         self.pb.set_position(pos as u64);
     }
 
+    fn byte_progress(&self, label: &str, pos: u64, total: u64) {
+        if pos != 0 && total != 0 {
+            self.pb.set_style(byte_style());
+        } else {
+            self.pb.set_style(spinner_style());
+        }
+        self.pb.set_message(label.to_string());
+        self.pb.set_length(total);
+        self.pb.set_position(pos);
+    }
+
     fn is_enabled(&self) -> bool {
         true
     }