agent_ui: Auto-capture file context on paste (#42982)

Closes #42972


https://github.com/user-attachments/assets/98f2d3dc-5682-4670-b636-fa8ea2495c69

Release Notes:

- Added automatic file context detection when pasting code into the AI
agent panel. Pasted code now displays as collapsible badges showing the
file path and line numbers (e.g., "app/layout.tsx (18-25)").

---------

Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>

crates/vim/src/normal/yank.rs

@@ -11,7 +11,6 @@ use editor::{ClipboardSelection, Editor, SelectionEffects};
 use gpui::Context;
 use gpui::Window;
 use language::Point;
-use multi_buffer::MultiBufferRow;
 use settings::Settings;
 
 struct HighlightOnYank;
@@ -198,11 +197,14 @@ impl Vim {
                 if kind.linewise() {
                     text.push('\n');
                 }
-                clipboard_selections.push(ClipboardSelection {
-                    len: text.len() - initial_len,
-                    is_entire_line: false,
-                    first_line_indent: buffer.indent_size_for_line(MultiBufferRow(start.row)).len,
-                });
+                clipboard_selections.push(ClipboardSelection::for_buffer(
+                    text.len() - initial_len,
+                    false,
+                    start..end,
+                    &buffer,
+                    editor.project(),
+                    cx,
+                ));
             }
         }