tlc: Sprint 3 C10 — Find dialog pre-fills from cursor entry

Previously Find dialog always opened with the default placeholder
('*.rs'). Now open_find_dialog() inspects the active panel's
cursor entry and uses its name as the initial pattern — so
pressing M-? with cursor on 'main.rs' opens the dialog with
'main.rs' already in the input, ready for refinement (e.g.
'main.rs~' for backups, 'main*' for variants).

Implementation:
  - find::FindDialog::new_with_pattern(start_dir, initial_pattern)
  - panel::Panel::cursor_entry() -> Option<&Entry>
  - widget::input::Input::set_text(s) mutable setter (the
    existing .text() builder consumes self)
  - dialog_ops::open_find_dialog() uses cursor entry name as
    the initial pattern; skips '..' and falls back to default
    when the panel is empty

Tests (2 new in find::tests):
  - new_with_pattern_prefills_pattern_input
  - new_with_pattern_empty_falls_back_to_default

Total: 1278 passing (was 1276; +2 new).

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

@@ -354,10 +354,24 @@ impl FileManager {
         Ok(())
     }
 
-    /// Open the M-? Find dialog.
+    /// Open the M-? Find dialog. The pattern input is pre-filled with
+    /// the cursor entry's name (so searching for the selected file's
+    /// pattern is the default); falls back to the default placeholder
+    /// if the cursor is on `..` or the panel is empty.
     pub fn open_find_dialog(&mut self) -> Result<()> {
         let start = self.active_panel().path().to_path_buf();
-        self.dialog = Some(DialogState::Find(Box::new(find::FindDialog::new(start))));
+        let pattern = self
+            .active_panel()
+            .cursor_entry()
+            .map(|e| e.name.clone())
+            .filter(|n| n != "..")
+            .unwrap_or_default();
+        let dialog = if pattern.is_empty() {
+            find::FindDialog::new(start)
+        } else {
+            find::FindDialog::new_with_pattern(start, &pattern)
+        };
+        self.dialog = Some(DialogState::Find(Box::new(dialog)));
         Ok(())
     }
 

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

@@ -129,7 +129,8 @@ pub struct FindDialog {
 }
 
 impl FindDialog {
-    /// Create a new Find dialog rooted at `start_dir`.
+    /// Create a new Find dialog rooted at `start_dir` with the default
+    /// placeholder pattern ("*.rs").
     #[must_use]
     pub fn new(start_dir: PathBuf) -> Self {
         let pattern = Input::new().label("Find").placeholder("*.rs");
@@ -147,6 +148,19 @@ impl FindDialog {
         }
     }
 
+    /// Create a new Find dialog rooted at `start_dir` with the
+    /// pattern input pre-filled from the user's current selection
+    /// (e.g. cursor filename). Empty `initial_pattern` falls back to
+    /// the default placeholder.
+    #[must_use]
+    pub fn new_with_pattern(start_dir: PathBuf, initial_pattern: &str) -> Self {
+        let mut dlg = Self::new(start_dir);
+        if !initial_pattern.is_empty() {
+            dlg.pattern.set_text(initial_pattern.to_string());
+        }
+        dlg
+    }
+
     /// Re-run the search against the current pattern and mode.
     /// Errors are stored in `last_error` rather than propagated, so
     /// the dialog stays interactive even when the user types an
@@ -779,4 +793,18 @@ mod tests {
             .expect("render must not panic");
         let _ = fs::remove_dir_all(&dir);
     }
+
+    #[test]
+    fn new_with_pattern_prefills_pattern_input() {
+        let d = FindDialog::new_with_pattern(PathBuf::from("/tmp"), "foo.rs");
+        assert_eq!(d.pattern.value(), "foo.rs");
+    }
+
+    #[test]
+    fn new_with_pattern_empty_falls_back_to_default() {
+        let d = FindDialog::new_with_pattern(PathBuf::from("/tmp"), "");
+        // Empty pattern leaves the input at the default placeholder
+        // (".value()" returns empty when no text was set).
+        assert_eq!(d.pattern.value(), "");
+    }
 }

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

@@ -260,6 +260,13 @@ impl Panel {
         &self.entries
     }
 
+    /// Entry under the cursor, or `None` if the cursor is past the
+    /// end of the entry list.
+    #[must_use]
+    pub fn cursor_entry(&self) -> Option<&Entry> {
+        self.entries.get(self.cursor)
+    }
+
     /// Current status message.
     #[must_use]
     pub fn message(&self) -> Option<&str> {

local/recipes/tui/tlc/source/src/widget/input.rs

@@ -99,6 +99,13 @@ impl Input {
         self
     }
 
+    /// Set the current text (mutable setter, used to pre-fill the
+    /// input after construction). Cursor moves to the end.
+    pub fn set_text(&mut self, s: impl Into<String>) {
+        self.text = s.into();
+        self.cursor = self.text.chars().count();
+    }
+
     /// Mark the input as focused.
     #[must_use]
     pub fn focused(mut self) -> Self {