fix(feishu): conform card form submission and model select to upstream

- read form data from action.form_value (Card 2.0) instead of formValue

- wrap custom steer input and submit in a form container with submit button

- reuse runModelCommand for dropdown model picks so IDs with multiple / keep working

- pass key when sending the help card so back-to-menu stays valid

- compute initial_index from {value} option arrays

- add in-flight tests for menu stop, steer dropdown, and steer form

test/channels/feishu/feishu-cards.test.mjs

@@ -2,8 +2,10 @@ import assert from 'node:assert/strict';
 import test from 'node:test';
 import {
   cardActionProbeCard,
+  customSteerCard,
   menuCard,
   menuHelpText,
+  modelCard,
 } from '../../../src/channels/feishu/feishu-cards.mjs';
 
 function buttons(value, result = []) {
@@ -17,6 +19,28 @@ function buttons(value, result = []) {
   return result;
 }
 
+function selects(value, result = []) {
+  if (Array.isArray(value)) {
+    for (const item of value) selects(item, result);
+    return result;
+  }
+  if (!value || typeof value !== 'object') return result;
+  if (value.tag === 'select_static') result.push(value);
+  for (const child of Object.values(value)) selects(child, result);
+  return result;
+}
+
+function forms(value, result = []) {
+  if (Array.isArray(value)) {
+    for (const item of value) forms(item, result);
+    return result;
+  }
+  if (!value || typeof value !== 'object') return result;
+  if (value.tag === 'form') result.push(value);
+  for (const child of Object.values(value)) forms(child, result);
+  return result;
+}
+
 test('menu exposes the increased command set and keeps repair number-only', () => {
   const card = JSON.parse(menuCard());
   assert.match(JSON.stringify(card), /6 · 修复卡片按钮/);
@@ -49,3 +73,57 @@ test('card-action probe carries only its action and opaque nonce', () => {
   }]);
   assert.throws(() => cardActionProbeCard('{{client_id}}'), /safe card-action probe nonce/);
 });
+
+test('custom steer card wraps input and submit in a form container', () => {
+  const card = JSON.parse(customSteerCard());
+  const form = forms(card)[0];
+  assert.ok(form, 'custom steer card must contain a form container');
+  assert.equal(form.name, 'steer_form');
+  const inputs = buttons(form).filter((element) => element.tag === 'input');
+  // inputs are not buttons; scan form.elements directly
+  const input = form.elements.find((element) => element.tag === 'input');
+  assert.equal(input?.name, 'steer_text');
+  const submit = form.elements.find((element) => element.tag === 'button');
+  assert.equal(submit?.form_action_type, 'submit');
+  assert.deepEqual(submit?.behaviors, [{
+    type: 'callback',
+    value: { action: 'steer', source: 'form' },
+  }]);
+  // 表单外的返回菜单按钮仍保留
+  const back = buttons(card).find((b) => b.behaviors?.[0]?.value?.action === 'back_to_menu');
+  assert.ok(back);
+});
+
+test('menu session dropdown highlights the currently bound session via initial_index', () => {
+  const sessions = [
+    { id: 'session-1', title: 'First' },
+    { id: 'session-2', title: 'Second' },
+    { id: 'session-3', title: 'Third' },
+  ];
+  const card = JSON.parse(menuCard({
+    currentSession: { id: 'session-2', title: 'Second' },
+    sessions,
+  }));
+  const pick = selects(card).find((s) => s.name === 'session_pick');
+  assert.ok(pick, 'menu must render a session dropdown');
+  // initial_index is 1-based; the currently bound session sits at index 2.
+  assert.equal(pick.initial_index, 2);
+});
+
+test('model card dropdown highlights the current model via initial_index', () => {
+  const catalog = {
+    groups: [
+      { id: 'openrouter', name: 'OpenRouter', models: [
+        { id: 'anthropic/claude-sonnet-4', name: 'Claude Sonnet 4' },
+        { id: 'deepseek/deepseek-chat', name: 'DeepSeek Chat' },
+      ] },
+    ],
+    current: { provider: 'openrouter', model: 'deepseek/deepseek-chat' },
+  };
+  const card = JSON.parse(modelCard(catalog));
+  const pick = selects(card).find((s) => s.name === 'model_pick');
+  assert.ok(pick, 'model card must render a dropdown');
+  // deepseek/deepseek-chat is the second option (1-based index 2), even
+  // though the id itself contains a `/`.
+  assert.equal(pick.initial_index, 2);
+});