feat(coding-agent): export run mode utilities with options interfaces

- Add PrintModeOptions interface, update runPrintMode signature
- Export InteractiveMode, InteractiveModeOptions, runPrintMode, PrintModeOptions, runRpcMode from main package
- Document run modes in docs/sdk.md with usage examples
- Update CHANGELOG

packages/coding-agent/src/index.ts

@@ -202,6 +202,14 @@ export {
 } from "./core/tools/index.js";
 // Main entry point
 export { main } from "./main.js";
+// Run modes for programmatic SDK usage
+export {
+	InteractiveMode,
+	type InteractiveModeOptions,
+	type PrintModeOptions,
+	runPrintMode,
+	runRpcMode,
+} from "./modes/index.js";
 // UI components for extensions
 export {
 	ArminComponent,