Fix lint script to respect biome.json excludes

The lint script now properly filters out files excluded in biome.json
when linting staged files. This prevents pre-commit hook failures when
staging files like CHANGELOG.md or package.json that are excluded from
linting.

Changes:
- Read and parse biome.json to extract exclude patterns
- Filter staged files against Biome's exclude patterns
- Add pattern matching logic to support glob patterns (**, *, etc.)

Author: jdalton

scripts/lint.mjs

@@ -3,7 +3,7 @@
  * Provides smart linting that can target affected files or lint everything.
  */
 
-import { existsSync } from 'node:fs'
+import { existsSync, readFileSync } from 'node:fs'
 import path from 'node:path'
 
 import { isQuiet } from './utils/flags.mjs'
@@ -35,6 +35,57 @@ const CONFIG_PATTERNS = [
   'eslint.config.*',
 ]
 
+/**
+ * Get Biome exclude patterns from biome.json.
+ */
+function getBiomeExcludePatterns() {
+  try {
+    const biomeConfigPath = path.join(process.cwd(), 'biome.json')
+    if (!existsSync(biomeConfigPath)) {
+      return []
+    }
+
+    const biomeConfig = JSON.parse(readFileSync(biomeConfigPath, 'utf8'))
+    const includes = biomeConfig['files']?.['includes'] ?? []
+
+    // Extract patterns that start with '!' (exclude patterns)
+    return (
+      includes
+        .filter(
+          pattern => typeof pattern === 'string' && pattern.startsWith('!'),
+        )
+        // Remove the '!' prefix
+        .map(pattern => pattern.slice(1))
+    )
+  } catch {
+    // If we can't read biome.json, return empty array
+    return []
+  }
+}
+
+/**
+ * Check if a file matches any of the exclude patterns.
+ */
+function isExcludedByBiome(file, excludePatterns) {
+  for (const pattern of excludePatterns) {
+    // Convert glob pattern to regex-like matching
+    // Support **/ for directory wildcards and * for filename wildcards
+    const regexPattern = pattern
+      // **/ matches any directory
+      .replace(/\*\*\//g, '.*')
+      // * matches any characters except /
+      .replace(/\*/g, '[^/]*')
+      // Escape dots
+      .replace(/\./g, '\\.')
+
+    const regex = new RegExp(`^${regexPattern}$`)
+    if (regex.test(file)) {
+      return true
+    }
+  }
+  return false
+}
+
 /**
  * Check if we should run all linters based on changed files.
  */
@@ -74,10 +125,21 @@ function filterLintableFiles(files) {
     '.yaml',
   ])
 
+  const biomeExcludePatterns = getBiomeExcludePatterns()
+
   return files.filter(file => {
     const ext = path.extname(file)
     // Only lint files that have lintable extensions AND still exist.
-    return lintableExtensions.has(ext) && existsSync(file)
+    if (!lintableExtensions.has(ext) || !existsSync(file)) {
+      return false
+    }
+
+    // Filter out files excluded by biome.json
+    if (isExcludedByBiome(file, biomeExcludePatterns)) {
+      return false
+    }
+
+    return true
   })
 }