fix(editor-ui): make text_input honor its authored box style

paint_text_field used to paint an unconditional white fill, a default
grey border and a 6px radius floor, with near-black value text — a model
embedding an input in its own styled wrapper zeroes all of that out
(fill:[], stroke thickness 0, cornerRadius 0) and got a glaring white
pill with a duplicate icon on a dark themed search bar. No authored fill
now paints no box, no authored stroke draws no border, radius is taken
as-is, and the value text color adapts to the authored fill's luminance.

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

@@ -50,6 +50,11 @@ pub fn widget_text_inset_left(w: &SceneWidget) -> f32 {
     }
 }
 
+/// Perceived luminance (0..1) of an opaque scene color.
+fn color_luminance(c: Color) -> f32 {
+    0.299 * c.r + 0.587 * c.g + 0.114 * c.b
+}
+
 /// Paint the static visual for a widget scene node, in world coords.
 ///
 /// `world_rect` is the node's already-zoom-scaled screen rect; `zoom`
@@ -249,14 +254,22 @@ fn paint_radio_group(cx: &mut PaintCx<'_>, w: &SceneWidget, r: Rect, zoom: f32)
 /// (near-black) or, when empty, the placeholder (muted).
 fn paint_text_field(cx: &mut PaintCx<'_>, node: &SceneNode, w: &SceneWidget, r: Rect, zoom: f32) {
     let (x, y, ww, h) = rect_parts(r);
-    let radius = (node.corner_radius * zoom).max(6.0 * zoom);
+    // Respect the AUTHORED box style. A model embedding an input into its own
+    // styled wrapper zeroes everything out (`fill: []`, `stroke.thickness: 0`,
+    // `cornerRadius: 0`) — the old unconditional white fill + grey border +
+    // 6px-radius floor painted a glaring white pill on top of a dark themed
+    // wrapper (measured on a dark dashboard's search bar). No fill → paint no
+    // box; no stroke → draw no border; radius as authored.
+    let radius = node.corner_radius * zoom;
     if let Some(fill) = node.fill {
         cx.backend.fill_round_rect(r, radius, fill);
-    } else {
-        cx.backend.fill_round_rect(r, radius, KNOB);
     }
-    let stroke_w = node.stroke.map(|s| s.width).unwrap_or(1.0) * zoom;
-    cx.backend.stroke_round_rect(r, radius, TRACK_OFF, stroke_w);
+    if let Some(stroke) = node.stroke {
+        if stroke.width > 0.0 {
+            cx.backend
+                .stroke_round_rect(r, radius, stroke.color, stroke.width * zoom);
+        }
+    }
 
     // Leading / trailing lucide glyphs at the content edges, vertically
     // centred. The text inset (`widget_text_inset_left`) reserves room
@@ -288,6 +301,19 @@ fn paint_text_field(cx: &mut PaintCx<'_>, node: &SceneNode, w: &SceneWidget, r:
     }
 
     if let Some((text, color)) = text_field_display_text(w) {
+        // The default value color (#111) assumed the old white box. On an
+        // authored DARK fill — or no box at all (transparent, blending into a
+        // dark wrapper) — flip it light; the muted placeholder grey reads on
+        // both. Only the VALUE color adapts.
+        let color = if color == TEXT_VALUE {
+            match node.fill {
+                Some(bg) if color_luminance(bg) >= 0.5 => TEXT_VALUE,
+                Some(_) => Color::rgb_u8(0xF5, 0xF5, 0xF5),
+                None => Color::rgb_u8(0x9C, 0xA3, 0xAF),
+            }
+        } else {
+            color
+        };
         let fs = 14.0 * zoom;
         // text_area top-aligns; single-line inputs vertically centre.
         let ty = if w.kind == "text_area" {