refactor(editor): unify toolbar icon buttons into one paint_icon_button helper

Adds button::paint_icon_button (full icon button = hover/pressed/active feedback on jian Button + centred icon) and paint_icon_button_feedback (the bg+active funnel). toolbar's paint_button now delegates to it instead of hand-rolling active-fill + ghost-feedback + draw_icon separately. All toolbar icon buttons (tool buttons + shape slot) now funnel hover/active rendering through one place. Active highlight now jian Button Primary (r6). Removed dead BUTTON_RADIUS.

crates/op-editor-ui/src/widgets/button.rs

@@ -1,4 +1,5 @@
-use crate::{Color, Rect, RenderBackend, Theme};
+use crate::widgets::icons::{draw_icon, Icon};
+use crate::{Color, Point2D, Rect, RenderBackend, Theme};
 use jian_widgets::components::button::{Button, ButtonVariant};
 use jian_widgets::{Density, Tokens};
 
@@ -77,6 +78,59 @@ pub(crate) fn paint_button_feedback_wash(
     }
 }
 
+/// Icon-button background + feedback, centralised on jian Button. `active` paints
+/// the solid primary highlight (e.g. the selected toolbar tool); inactive uses the
+/// ghost hover/press wash. Returns the icon color to stroke on top — every icon
+/// button funnels its hover/active rendering through here instead of hand-rolling it.
+pub(crate) fn paint_icon_button_feedback(
+    backend: &mut dyn RenderBackend,
+    theme: &Theme,
+    rect: Rect,
+    hovered: bool,
+    pressed: bool,
+    active: bool,
+) -> Color {
+    if active {
+        Button {
+            label: "",
+            icon_d: None,
+            variant: ButtonVariant::Primary,
+            enabled: true,
+            hovered,
+            pressed,
+            font_size: 0.0,
+        }
+        .paint(backend, rect, &tokens_from_theme(theme));
+        theme.primary_foreground
+    } else {
+        paint_ghost_button_feedback(backend, theme, rect, hovered, pressed)
+    }
+}
+
+/// A complete icon button: hover / pressed / active feedback (centralised on
+/// jian Button) PLUS the centred icon glyph — so every toolbar and chrome icon
+/// button is a single call instead of hand-rolling `feedback + draw_icon`
+/// separately in each widget. `active` paints the solid primary highlight.
+#[allow(clippy::too_many_arguments)]
+pub(crate) fn paint_icon_button(
+    backend: &mut dyn RenderBackend,
+    theme: &Theme,
+    rect: Rect,
+    icon: Icon,
+    hovered: bool,
+    pressed: bool,
+    active: bool,
+    icon_size: f32,
+    stroke_w: f32,
+) {
+    let color = paint_icon_button_feedback(backend, theme, rect, hovered, pressed, active);
+    let origin = Point2D::new(
+        rect.origin.x + (rect.size.x - icon_size) / 2.0,
+        rect.origin.y + (rect.size.y - icon_size) / 2.0,
+    );
+    draw_icon(backend, icon, origin, icon_size, color, stroke_w);
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/op-editor-ui/src/widgets/toolbar.rs

@@ -25,7 +25,6 @@ use op_editor_core::Tool;
 /// Outer column width (matches the TS app's `w-12` toolbar).
 pub const TOOLBAR_WIDTH: f32 = 44.0;
 const BUTTON_SIZE: f32 = 32.0;
-const BUTTON_RADIUS: f32 = 8.0;
 const ICON_SIZE: f32 = 18.0;
 const STROKE_W: f32 = 1.6;
 const BUTTON_GAP: f32 = 4.0;
@@ -454,29 +453,15 @@ fn paint_button(
         origin: Point2D::new(x, y),
         size: Point2D::new(BUTTON_SIZE, BUTTON_SIZE),
     };
-    let icon_color = if active {
-        cx.backend
-            .fill_round_rect(button_rect, BUTTON_RADIUS, theme.primary);
-        theme.primary_foreground
-    } else {
-        crate::widgets::button::paint_ghost_button_feedback(
-            cx.backend,
-            theme,
-            button_rect,
-            hovered,
-            pressed,
-        )
-    };
-    let icon_origin = Point2D::new(
-        x + (BUTTON_SIZE - ICON_SIZE) / 2.0,
-        y + (BUTTON_SIZE - ICON_SIZE) / 2.0,
-    );
-    draw_icon(
+    crate::widgets::button::paint_icon_button(
         cx.backend,
+        theme,
+        button_rect,
         icon,
-        icon_origin,
+        hovered,
+        pressed,
+        active,
         ICON_SIZE,
-        icon_color,
         STROKE_W,
     );
 }