feat(studio): add HDR warning banner and Apply-to-scope row, completing FlatColorGradingSection

Also adds a not-busy click assertion for the Apply button so
onApplyToScope is exercised end-to-end, not just its disabled state.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

packages/studio/src/components/editor/propertyPanelFlatColorGradingSection.test.tsx

@@ -370,3 +370,59 @@ describe("FlatColorGradingSection — Effects", () => {
     act(() => root.unmount());
   });
 });
+
+describe("FlatColorGradingSection — HDR banner and Apply scope", () => {
+  it("shows the HDR banner only when mediaMetadata reports an HDR source", () => {
+    const { host, root } = renderInto(
+      <FlatColorGradingSection
+        {...neutralPropsBase()}
+        mediaMetadata={{
+          kind: "video",
+          color: { dynamicRange: "hdr", hdrTransfer: "pq", label: "HDR10", isHdr: true },
+        }}
+      />,
+    );
+    expect(host.textContent).toContain("SDR preview");
+    act(() => root.unmount());
+  });
+
+  it("omits the HDR banner for SDR media", () => {
+    const { host, root } = renderInto(
+      <FlatColorGradingSection
+        {...neutralPropsBase()}
+        mediaMetadata={{
+          kind: "video",
+          color: { dynamicRange: "sdr", hdrTransfer: null, label: "SDR", isHdr: false },
+        }}
+      />,
+    );
+    expect(host.textContent).not.toContain("SDR preview");
+    act(() => root.unmount());
+  });
+
+  it("fires onApplyToScope from the Apply button, respecting applyBusy", () => {
+    const onApplyToScope = vi.fn();
+    const { host, root } = renderInto(
+      <FlatColorGradingSection {...neutralPropsBase()} onApplyToScope={onApplyToScope} applyBusy />,
+    );
+    const applyButton = host.querySelector<HTMLButtonElement>('[data-flat-grade-apply="true"]');
+    expect(applyButton?.disabled).toBe(true);
+    act(() => root.unmount());
+  });
+
+  it("fires onApplyToScope exactly once when the Apply button is clicked while not busy", () => {
+    const onApplyToScope = vi.fn();
+    const { host, root } = renderInto(
+      <FlatColorGradingSection
+        {...neutralPropsBase()}
+        onApplyToScope={onApplyToScope}
+        applyBusy={false}
+      />,
+    );
+    const applyButton = host.querySelector<HTMLButtonElement>('[data-flat-grade-apply="true"]');
+    expect(applyButton?.disabled).toBe(false);
+    act(() => applyButton?.dispatchEvent(new MouseEvent("click", { bubbles: true })));
+    expect(onApplyToScope).toHaveBeenCalledTimes(1);
+    act(() => root.unmount());
+  });
+});

packages/studio/src/components/editor/propertyPanelFlatColorGradingSection.tsx

@@ -138,18 +138,39 @@ const EFFECT_SLIDERS: Array<{ key: HfColorGradingEffectKey; label: string }> = [
   { key: "pixelate", label: "Pixelate" },
 ];
 
+function HdrBanner({ metadata }: { metadata: MediaMetadata | null }) {
+  if (metadata?.color.dynamicRange !== "hdr") return null;
+  return (
+    <div
+      data-flat-grade-hdr-banner="true"
+      className="rounded-md border border-amber-500/30 bg-amber-500/10 px-2.5 py-1.5 text-[10px] leading-4 text-amber-100"
+    >
+      <div className="mb-0.5 flex items-center justify-between gap-2">
+        <span className="font-semibold">{metadata.color.label} source</span>
+        <span className="rounded bg-amber-400/20 px-1.5 py-0.5 text-[9px] font-semibold uppercase tracking-wide text-amber-100">
+          SDR preview
+        </span>
+      </div>
+      <p className="text-amber-100/80">
+        These controls use the current SDR shader preview path. Render may stay HDR-tagged, but this
+        is not true HDR color grading yet.
+      </p>
+    </div>
+  );
+}
+
 // fallow-ignore-next-line complexity
 export function FlatColorGradingSection({
   grading,
   assets,
   onImportAssets,
   onCommitColorGrading,
-  applyScope: _applyScope,
+  applyScope,
-  applyBusy: _applyBusy,
+  applyBusy,
-  onSetApplyScope: _onSetApplyScope,
+  onSetApplyScope,
-  onApplyToScope: _onApplyToScope,
+  onApplyToScope,
-  onApplyScopeAvailable: _onApplyScopeAvailable,
+  onApplyScopeAvailable,
-  mediaMetadata: _mediaMetadata,
+  mediaMetadata,
 }: {
   grading: NormalizedHfColorGrading;
   assets: string[];
@@ -218,6 +239,7 @@ export function FlatColorGradingSection({
 
   return (
     <div className="space-y-1.5">
+      <HdrBanner metadata={mediaMetadata} />
       <div data-flat-grade-preset="true" className="flex min-h-[30px] items-center justify-between">
         <span className="text-[11px] text-panel-text-2">Preset</span>
         <FlatSelectRow
@@ -424,6 +446,32 @@ export function FlatColorGradingSection({
           );
         })}
       </div>
+
+      {onApplyScopeAvailable && (
+        <div className="flex items-center justify-between gap-2 border-t border-panel-hairline pt-1.5">
+          <span className="flex items-center gap-1.5 text-[11px] text-panel-text-2">
+            Copy grade to
+            <select
+              value={applyScope}
+              onChange={(e) => onSetApplyScope(e.target.value as "source-file" | "project")}
+              disabled={applyBusy}
+              className="bg-transparent font-mono text-[11px] text-panel-text-0 outline-none disabled:opacity-50"
+            >
+              <option value="source-file">Current file media</option>
+              <option value="project">All project media</option>
+            </select>
+          </span>
+          <button
+            type="button"
+            data-flat-grade-apply="true"
+            disabled={applyBusy}
+            onClick={onApplyToScope}
+            className="text-[11px] font-medium text-panel-accent hover:text-panel-accent/80 disabled:cursor-not-allowed disabled:opacity-50"
+          >
+            {applyBusy ? "Applying" : "Apply"}
+          </button>
+        </div>
+      )}
     </div>
   );
 }