feat(config): add source map support for coverage tracking

- Import envAsBoolean from @socketsecurity/lib/env/helpers
- Enable source maps conditionally when COVERAGE env var is set
- Update vitest coverage exclusions to prevent dist/ file tracking
- Add multiple exclusion patterns for better coverage accuracy

This improves coverage measurement by generating source maps during
coverage runs, though architectural limitations prevent full src/
coverage remapping.

Author: jdalton

.config/esbuild.config.mjs

@@ -7,14 +7,9 @@ import path from 'node:path'
 import { fileURLToPath } from 'node:url'
 import fg from 'fast-glob'
 
+import { envAsBoolean } from '#socketsecurity/lib/env/helpers'
 import { getLocalPackageAliases } from '../scripts/utils/get-local-package-aliases.mjs'
 
-// Helper to check boolean env vars
-const envAsBoolean = name => {
-  const value = process.env[name]
-  return value === 'true' || value === '1'
-}
-
 const __dirname = path.dirname(fileURLToPath(import.meta.url))
 const rootPath = path.join(__dirname, '..')
 const srcPath = path.join(rootPath, 'src')
@@ -293,7 +288,7 @@ export const buildConfig = {
   platform: 'node',
   target: 'node18',
   // Enable source maps for coverage (set COVERAGE=true env var)
-  sourcemap: envAsBoolean('COVERAGE'),
+  sourcemap: envAsBoolean(process.env.COVERAGE),
   // Don't minify - this is a library and minification breaks ESM/CJS interop.
   minify: false,
   // Tree-shaking optimization.

.config/vitest.config.mts

@@ -132,8 +132,11 @@ export default defineConfig({
         'test/**',
         'packages/**',
         'perf/**',
-        'dist/**',
-        'src/external/**',
+        'dist',
+        'dist/**/*',
+        '**/dist/**',
+        'src/external',
+        'src/external/**/*',
         'src/types.ts',
         'scripts/**',
       ],