feat(lint): flag unrecognized typography sub-properties

packages/cli/src/linter/model/handler.test.ts

@@ -366,6 +366,20 @@ describe('ModelHandler', () => {
       const headline = result.designSystem.typography.get('headline');
       expect(headline?.fontWeight).toBe(700);
     });
+
+    it('warns about unrecognized typography sub-properties that are silently dropped', () => {
+      const result = handler.execute(makeParsed({
+        typography: {
+          'headline': { fontFamily: 'Inter', textTransform: 'uppercase' },
+        },
+      }));
+      const warning = result.findings.find(f => f.path === 'typography.headline.textTransform');
+      expect(warning).toBeDefined();
+      expect(warning?.severity).toBe('warning');
+      // The recognized property is still resolved, and known props never warn.
+      expect(result.designSystem.typography.get('headline')?.fontFamily).toBe('Inter');
+      expect(result.findings.some(f => f.path === 'typography.headline.fontFamily')).toBe(false);
+    });
   });
 
   describe('rounded validation', () => {

packages/cli/src/linter/model/handler.ts

@@ -25,7 +25,7 @@ import type {
   Finding,
 } from './spec.js';
 
-import { isValidColor, isParseableDimension, isTokenReference, parseDimensionParts } from './spec.js';
+import { isValidColor, isParseableDimension, isTokenReference, parseDimensionParts, VALID_TYPOGRAPHY_PROPS } from './spec.js';
 import { parseCssColor } from './color-parser.js';
 
 import {
@@ -34,6 +34,7 @@ import {
 } from '../spec-config.js';
 
 const SCHEMA_KEY_SET: ReadonlySet<string> = new Set(SCHEMA_KEYS);
+const TYPOGRAPHY_PROP_SET: ReadonlySet<string> = new Set(VALID_TYPOGRAPHY_PROPS);
 
 /**
  * Builds a resolved DesignSystemState from parsed YAML tokens.
@@ -367,6 +368,19 @@ function parseTypography(props: Record<string, string | number>, path: string, f
     }
   }
 
+  // Surface typography sub-properties that aren't part of the schema: they are
+  // silently dropped (never resolved or emitted), so warn rather than ignore —
+  // mirroring how unknown component sub-tokens are reported.
+  for (const key of Object.keys(props)) {
+    if (!TYPOGRAPHY_PROP_SET.has(key)) {
+      findings.push({
+        severity: 'warning',
+        path: `${path}.${key}`,
+        message: `'${key}' is not a recognized typography property. Valid properties: ${VALID_TYPOGRAPHY_PROPS.join(', ')}.`,
+      });
+    }
+  }
+
   return result;
 }