fix: display resolved value of 0 in token tooltip

The AliasBadge component used `value || ''` which treated 0 as falsy,
causing the tooltip to show an empty string instead of '0'. Changed to
`value ?? ''` to only fall back for null/undefined.

Fixes #3776

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Copilot

.changeset/fix-tooltip-zero-value.md

@@ -0,0 +1,5 @@
+---
+"@tokens-studio/figma-plugin": patch
+---
+
+Fix token tooltip not displaying resolved value when value is 0

packages/tokens-studio-for-figma/src/app/components/TokenTooltip/AliasBadge.tsx

@@ -21,7 +21,7 @@ export default function AliasBadge({ value }: Props) {
 
   return (
     <StyledAliasBadge>
-      {formatTokenValueForDisplay(value || '', currentBaseFontSize)}
+      {formatTokenValueForDisplay(value ?? '', currentBaseFontSize)}
     </StyledAliasBadge>
   );
 }

packages/tokens-studio-for-figma/src/app/components/TokenTooltip/TokenTooltipContent.test.tsx

@@ -216,6 +216,20 @@ const tokens: SingleToken[] = [
     description: 'a broken reference',
     failedToResolve: true,
   },
+  {
+    name: 'spacing.none',
+    type: TokenTypes.SPACING,
+    value: 0,
+    rawValue: 0,
+    description: 'zero value token',
+  },
+  {
+    name: 'spacing.alias',
+    type: TokenTypes.SPACING,
+    value: 0,
+    rawValue: '{spacing.none}',
+    description: 'alias to zero value token',
+  },
   {
     name: 'border.regular',
     type: TokenTypes.BORDER,
@@ -420,4 +434,22 @@ describe('TokenTooltip alias', () => {
     expect(getByText(String('brokentoken'))).toBeInTheDocument();
     expect(getByTestId('not-found-badge')).toBeInTheDocument();
   });
+
+  it('displays resolved value of 0 correctly', () => {
+    const { getByText } = render(
+      <TokensContext.Provider value={customStore}>
+        <TokenTooltipContent
+          token={{
+            name: 'spacing.alias',
+            type: TokenTypes.SPACING,
+            value: '{spacing.none}',
+            rawValue: '{spacing.none}',
+            description: 'alias to zero value token',
+          }}
+        />
+      </TokensContext.Provider>,
+    );
+
+    expect(getByText('0')).toBeInTheDocument();
+  });
 });