fix(lint): handle Biome 'no files processed' as success

When Biome receives files that are excluded by its configuration
(e.g., package.json, CHANGELOG.md), it exits with an error stating
"No files were processed in the specified paths". This is not a real
error - it just means Biome had nothing to do.

This change detects this specific error message and treats it as
success, allowing the linter to continue to the next linter (eslint)
instead of failing the entire lint run.

Fixes spurious lint failures in git hooks when staging files that
Biome doesn't process.

Author: jdalton

scripts/lint.mjs

@@ -195,6 +195,16 @@ async function runLintOnFiles(files, options = {}) {
     const result = await runCommandQuiet('pnpm', args)
 
     if (result.exitCode !== 0) {
+      // Check if Biome simply had no files to process (not an error)
+      const isBiomeNoFilesError = result.stderr?.includes(
+        'No files were processed in the specified paths',
+      )
+
+      if (isBiomeNoFilesError) {
+        // Biome had nothing to do - this is fine, continue to next linter
+        continue
+      }
+
       // When fixing, non-zero exit codes are normal if fixes were applied.
       if (!fix || (result.stderr && result.stderr.trim().length > 0)) {
         if (!quiet) {
@@ -259,6 +269,16 @@ async function runLintOnAll(options = {}) {
     const result = await runCommandQuiet('pnpm', args)
 
     if (result.exitCode !== 0) {
+      // Check if Biome simply had no files to process (not an error)
+      const isBiomeNoFilesError = result.stderr?.includes(
+        'No files were processed in the specified paths',
+      )
+
+      if (isBiomeNoFilesError) {
+        // Biome had nothing to do - this is fine, continue to next linter
+        continue
+      }
+
       // When fixing, non-zero exit codes are normal if fixes were applied.
       if (!fix || (result.stderr && result.stderr.trim().length > 0)) {
         if (!quiet) {