feat(xref): per-row path actions and right-click row selection

Row menu Select New Path and Find and Replace now act on the right-clicked row via dedicated XrefRowPathPick / XrefRowFindReplacePrompt messages (prefill + command-line focus, XOPEN output included). Rows use a RightClickArea wrapper so right-click selects the row even though ContextMenu captures the press, and opening or acting on the menu resets the Change Path Type flyout state.

src/app/mod.rs

@@ -2403,6 +2403,10 @@ pub enum Message {
     /// Prefill the command line for Find & Replace across references
     /// (`XREF Path Find <old> <new>`); the CLI parses and runs it.
     XrefFindReplacePrompt,
+    /// Pick a new path for a specific row index.
+    XrefRowPathPick(usize),
+    /// Prefill the command line for Find & Replace for a specific row index.
+    XrefRowFindReplacePrompt(usize),
     XrefRowChangePathEnter,
     XrefRowChangePathLeave,
     LayerToggleVisible(usize),