feat(adapter): add instructionsFilePath to config types and UI builders

Wire up instructionsFilePath in CreateConfigValues, adapter docs, and
UI config builders for both Claude and Codex adapters.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/adapter-utils/src/types.ts

@@ -157,6 +157,7 @@ export interface CLIAdapterModule {
 export interface CreateConfigValues {
   adapterType: string;
   cwd: string;
+  instructionsFilePath?: string;
   promptTemplate: string;
   model: string;
   thinkingEffort: string;