feat(xref): 8-item filtered row menu, preview on selection, details display size

Row right-click menu is exactly Open, Attach..., Unload, Reload, Detach, Change Path Type group with Make Absolute, Make Relative, Remove Path, Select New Path, Find and Replace. Change Path Type renders as indented group. Open uses OCS for DWG and OS default for images and PDFs. Preview decodes on selection change, not only at refresh. Details shows placed display width and height for image instances.

src/app/update/dialog.rs

@@ -924,6 +924,7 @@ pub(super) fn on_ribbon_tool_click(&mut self, tool_id: String, event: ModuleEven
             return;
         }
         let label = match op {
+            XrefPaletteOp::Open => "XREF-OPEN",
             XrefPaletteOp::Detach => "XREF-DETACH",
             XrefPaletteOp::Unload => "XREF-UNLOAD",
             XrefPaletteOp::Reload => "XREF-RELOAD",
@@ -1190,6 +1191,9 @@ pub(super) fn on_ribbon_tool_click(&mut self, tool_id: String, event: ModuleEven
                     }
                 }
             }
+            XrefPaletteOp::Open | XrefPaletteOp::Attach => {
+                // Handled in update/mod.rs XrefRowOp dispatch (navigation / picker), not here.
+            }
         }
         if done > 0 {
             self.post_ref_op(i);