M3.17: interactive gradient annotator — drag the start handle or the bar to move the gradient, the end handle to change length and angle, just past the end to rotate (Shift snaps to 45°); a bar click adds a stop, stops drag along the bar, off it to delete (never below two), Alt-drag copies, diamonds move midpoints; a click inside selected art applies the gradient from that point; double-clicking a stop opens a popover (Color/Swatches, Opacity, Location); the selected stop lives in the session (gradient.selectStop), shared by the tool, the Gradient and Color panels and agents, and takes Delete/Backspace and ←/→ ahead of their shortcuts (Tool::claims_key, also headless); stop chips draw as Overlay::Swatch with generated add/remove-stop cursors; the stop math moves into the color crate

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/tooling.rs

@@ -79,6 +79,7 @@ impl Session {
             snap_to_point: view.snap_to_point,
             corner_widgets: view.corner_widgets,
             fill_active: self.fill_active,
+            gradient_stop: self.gradient_stop,
         };
         f(self.tool.as_mut(), &cx)
     }
@@ -109,6 +110,11 @@ impl Session {
         self.tool.busy()
     }
 
+    /// Does the active tool take `key` ahead of the shortcuts bound to it (see `Tool::claims_key`)?
+    pub fn tool_claims_key(&mut self, key: ToolKey, view: ViewInfo) -> bool {
+        self.with_tool_cx(view, |t, cx| t.claims_key(cx, key))
+    }
+
     pub fn overlays(&mut self, view: ViewInfo) -> Vec<Overlay> {
         let mut v = self.with_tool_cx(view, |t, cx| t.overlays(cx));
         if let Some(d) = self.active() {