feat(cli): implement output abstraction layer

packages/cli/src/output/quiet.ts

@@ -0,0 +1,27 @@
+/**
+ * Quiet renderer for CLI output.
+ *
+ * Outputs only ID fields, one per line. Useful for scripting and pipelines.
+ */
+
+import type { AnyCommandResult, OutputOptions } from './types.js'
+
+/** Extract ID from item using schema definition */
+function getId<T>(item: T, idField: keyof T | ((item: T) => string)): string {
+  if (typeof idField === 'function') {
+    return idField(item)
+  }
+  return String(item[idField])
+}
+
+/** Render command result in quiet mode (IDs only) */
+export function renderQuiet<T>(
+  result: AnyCommandResult<T>,
+  _options: OutputOptions
+): string {
+  if (result.type === 'single') {
+    return getId(result.data, result.schema.idField)
+  } else {
+    return result.data.map((item) => getId(item, result.schema.idField)).join('\n')
+  }
+}