fix(xref): Change Path Type flyout with hover reveal

The Change Path Type row shows a right-triangle affordance and reveals the Make Absolute / Make Relative / Remove Path submenu beside it. The flyout opens on hover only and a shared submenu-row style removes dead code from the earlier iterations.

src/app/mod.rs

@@ -2403,6 +2403,8 @@ pub enum Message {
     /// Prefill the command line for Find & Replace across references
     /// (`XREF Path Find <old> <new>`); the CLI parses and runs it.
     XrefFindReplacePrompt,
+    XrefRowChangePathEnter,
+    XrefRowChangePathLeave,
     LayerToggleVisible(usize),
     LayerToggleLock(usize),
     LayerToggleFreeze(usize),