Show active tracking reference tooltip

src/app/mod.rs

@@ -430,6 +430,9 @@ pub(super) struct OpenCADStudio {
     /// cursor is on a tracking ray. Lets a typed distance place a point along
     /// the ray from the tracking point (issue #69). `None` when not aligned.
     otrack_active: Option<(glam::DVec3, glam::DVec3)>,
+    /// Kind of the currently active tracking reference, kept separately from
+    /// `otrack_active` so typed-distance behavior remains unchanged.
+    otrack_kind: Option<crate::snap::TrackingKind>,
     /// Whether Tangent snap was enabled before a tangent-pick command started.
     pre_cmd_tangent: Option<bool>,
     /// Drawing defaults captured by ADDSELECTED before it adopts the template
@@ -3052,6 +3055,7 @@ impl OpenCADStudio {
             annotation_auto_scale: -4,
             last_saved_config: None,
             otrack_active: None,
+            otrack_kind: None,
             clean_screen: false,
             quick_properties: false,
             quick_properties_anchor: Point::new(12.0, 12.0),