fix(studio): right-align FlatRow's value input in the flat inspector

FlatRow lays out label…gap…value across a `justify-between` row, but the
shared CommitField input it wraps had no text-align, so its text hugged
the LEFT edge of the value's own (often much wider) right-hand box —
looking left-aligned relative to the row, out of step with FlatSelectRow
and FlatSlider, which already right-align.

Added an optional `align` prop to CommitField (default "left", preserving
the legacy panel's MetricField/DetailField layouts where label-then-value
sits inline and left reads naturally) and pass `align="right"` from
FlatRow. Left the Motion Timing row's Start/End/Duration cells alone —
those stack label-above-value in a grid, a different pattern from the
inline label…value row this fix targets.

New tests: FlatRow's input has `text-right` (not `text-left`); the legacy
MetricField's input keeps `text-left` (not `text-right`), pinning
CommitField's default so the shared component doesn't drift for the
panel that didn't ask for this.

Full studio suite (2645 tests) green; typecheck/oxlint/oxfmt clean.

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

@@ -38,6 +38,16 @@ describe("FlatRow", () => {
     act(() => root.unmount());
   });
 
+  it("right-aligns the value input — the flat inspector's justify-between row layout leaves a left-aligned value looking stranded at the edge of its own box", () => {
+    const { host, root } = renderInto(
+      <FlatRow label="Size" value="72px" tier="explicitCustom" onCommit={vi.fn()} />,
+    );
+    const input = host.querySelector("input");
+    expect(input?.className).toContain("text-right");
+    expect(input?.className).not.toContain("text-left");
+    act(() => root.unmount());
+  });
+
   it("renders the explicitCustom tier with a mint value and a reset button", () => {
     const onReset = vi.fn();
     const { host, root } = renderInto(

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

@@ -51,6 +51,7 @@ export function FlatRow({
             value={value}
             disabled={disabled}
             liveCommit={liveCommit}
+            align="right"
             onCommit={(nextValue) => {
               track("metric", label);
               onCommit(nextValue);

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

@@ -134,6 +134,13 @@ describe("classic property-panel primitive telemetry", () => {
     const input = host.querySelector("input");
     if (!input) throw new Error("expected metric input");
 
+    // Regression guard for CommitField's shared `align` default: the classic
+    // panel lays out label-then-value inline, where left-aligned reads
+    // naturally — this must stay left even though the flat inspector's
+    // FlatRow now opts into `align="right"` for its own justify-between rows.
+    expect(input.className).toContain("text-left");
+    expect(input.className).not.toContain("text-right");
+
     act(() => blurInput(input));
     expect(trackStudioEvent).not.toHaveBeenCalled();
 

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

@@ -9,11 +9,17 @@ export function CommitField({
   value,
   disabled,
   liveCommit,
+  align = "left",
   onCommit,
 }: {
   value: string;
   disabled?: boolean;
   liveCommit?: boolean;
+  /** The legacy panel lays out label-then-value inline (left reads naturally);
+   *  the flat inspector lays out label…value across a `justify-between` row,
+   *  where a left-aligned value looks stranded at the edge of its own
+   *  right-hand box instead of lining up with every other row's value. */
+  align?: "left" | "right";
   onCommit: (nextValue: string) => void;
 }) {
   const [draft, setDraft] = useState(value);
@@ -92,7 +98,9 @@ export function CommitField({
         scheduleCommit(nextDraft);
       }}
       title={parseNumericToken(value) ? "Scroll or use Arrow keys to adjust" : undefined}
-      className="min-w-0 w-full bg-transparent text-[11px] font-medium text-neutral-100 outline-none disabled:cursor-not-allowed disabled:text-neutral-600"
+      className={`min-w-0 w-full bg-transparent text-[11px] font-medium text-neutral-100 outline-none disabled:cursor-not-allowed disabled:text-neutral-600 ${
+        align === "right" ? "text-right" : "text-left"
+      }`}
     />
   );
 }