tlc: Sprint 3 C3 — delete dialog shows total recursive size

DeleteDialog header now includes the total recursive size of
all paths to be deleted (formatted via format_size). For example:
  'Delete 3 (1.2 MB) ?'  instead of just 'Delete ?'.
Computed eagerly at construction via crate::ops::count_bytes so
render() does not block on filesystem traversal.

DeleteDialog (delete_dialog.rs):
  - New field total_bytes: u64 (cached at construction)
  - new() calls crate::ops::count_bytes(&paths) to populate it
  - render() prepends '(N items)' to header and appends size when > 0

Tests (3 new in delete_dialog::tests):
  - new_computes_total_bytes_for_directory (recursive dir sum)
  - new_total_bytes_zero_for_missing_paths
  - new_total_bytes_sums_multiple_paths

Total: 1271 passing (was 1268; +3 new).

local/recipes/tui/tlc/source/src/filemanager/delete_dialog.rs

@@ -25,6 +25,10 @@ use crate::widget::button::{ButtonKind, ButtonSpec};
 pub struct DeleteDialog {
     /// Paths to be deleted.
     pub paths: Vec<PathBuf>,
+    /// Cached total size in bytes (recursive sum across all paths).
+    /// Computed at construction via `crate::ops::count_bytes` so the
+    /// dialog renders without blocking on filesystem traversal.
+    pub total_bytes: u64,
     /// True after Y confirms.
     pub confirmed: bool,
     /// True after N / Esc cancels.
@@ -36,11 +40,16 @@ pub struct DeleteDialog {
 }
 
 impl DeleteDialog {
-    /// Create a new delete dialog for the given paths.
+    /// Create a new delete dialog for the given paths. The total
+    /// recursive size is computed eagerly (filesystem walk) so the
+    /// dialog header can display "Delete N items (X MB)?" without
+    /// blocking at render time.
     #[must_use]
     pub fn new(paths: Vec<PathBuf>) -> Self {
+        let total_bytes = crate::ops::count_bytes(&paths);
         Self {
             paths,
+            total_bytes,
             confirmed: false,
             cancelled: false,
             width_pct: 0.5,
@@ -105,7 +114,16 @@ impl DeleteDialog {
             ])
             .split(inner);
 
-        let header_text = format!("{} ?", crate::locale::t("dialog_title_delete"));
+        let header_text = if self.total_bytes > 0 {
+            format!(
+                "{} {} ({} ?)",
+                crate::locale::t("dialog_title_delete"),
+                self.paths.len(),
+                crate::filemanager::format_utils::format_size(self.total_bytes)
+            )
+        } else {
+            format!("{} {} ?", crate::locale::t("dialog_title_delete"), self.paths.len())
+        };
         let header = Line::from(Span::styled(
             header_text,
             Style::default()
@@ -207,4 +225,34 @@ mod tests {
         assert!(d.is_cancelled());
         assert!(!d.is_confirmed());
     }
+
+    #[test]
+    fn new_computes_total_bytes_for_directory() {
+        let dir = tempfile::tempdir().unwrap();
+        let sub = dir.path().join("sub");
+        std::fs::create_dir(&sub).unwrap();
+        std::fs::write(sub.join("a.txt"), b"hello").unwrap();
+        std::fs::write(sub.join("b.txt"), b"world!!").unwrap();
+        let d = DeleteDialog::new(vec![dir.path().to_path_buf()]);
+        // Recursive sum: 5 + 7 = 12 bytes (directories don't count
+        // their own entries).
+        assert_eq!(d.total_bytes, 12);
+    }
+
+    #[test]
+    fn new_total_bytes_zero_for_missing_paths() {
+        let d = DeleteDialog::new(vec![std::path::PathBuf::from("/no/such/path/xyz")]);
+        assert_eq!(d.total_bytes, 0);
+    }
+
+    #[test]
+    fn new_total_bytes_sums_multiple_paths() {
+        let dir = tempfile::tempdir().unwrap();
+        let p1 = dir.path().join("a");
+        let p2 = dir.path().join("b");
+        std::fs::write(&p1, b"12345").unwrap();
+        std::fs::write(&p2, b"678").unwrap();
+        let d = DeleteDialog::new(vec![p1, p2]);
+        assert_eq!(d.total_bytes, 8);
+    }
 }