fix(workflows): add text_mode config for Claude Code remote session compatibility (#1214)

- Add workflow.text_mode config option (default: false) that replaces
  AskUserQuestion TUI menus with plain-text numbered lists
- Document --text flag and config-set workflow.text_mode true as the
  fix for /rc remote sessions where the Claude App cannot forward TUI
  menu selections
- Update discuss-phase.md with text mode parsing and answer_validation
  fallback documentation
- Add text_mode to loadConfig defaults and VALID_CONFIG_KEYS
- Add regression tests for config-set and loadConfig

tests/core.test.cjs

@@ -61,6 +61,7 @@ describe('loadConfig', () => {
     assert.strictEqual(config.brave_search, false);
     assert.strictEqual(config.parallelization, true);
     assert.strictEqual(config.nyquist_validation, true);
+    assert.strictEqual(config.text_mode, false);
   });
 
   test('reads model_profile from config.json', () => {