feat: /last and bind button for previous Q/A context (v0.3.4)

After attaching a session, show a button and /last command that load the latest human/assistant turn via session.history so phone users can continue with context.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/history.test.ts

@@ -0,0 +1,38 @@
+import assert from 'node:assert/strict'
+import test from 'node:test'
+import { extractLastTurn, formatLastTurn } from '../src/history.ts'
+
+test('extractLastTurn pairs latest human user with following assistant', () => {
+  const turn = extractLastTurn([
+    {
+      type: 'user/message',
+      data: { source: { kind: 'plugin', plugin: 'x' }, content: [{ type: 'text', text: 'injected' }] },
+    },
+    {
+      type: 'user/message',
+      data: { source: { kind: 'user' }, content: [{ type: 'text', text: '第一问' }] },
+    },
+    {
+      type: 'assistant/message',
+      data: { message: { content: [{ type: 'text', text: '第一答' }] } },
+    },
+    {
+      type: 'user/message',
+      data: { source: { kind: 'user' }, content: [{ type: 'text', text: '第二问' }] },
+    },
+    {
+      type: 'assistant/message',
+      data: { message: { content: [{ type: 'text', text: '第二答' }] } },
+    },
+  ])
+  assert.equal(turn.userText, '第二问')
+  assert.equal(turn.assistantText, '第二答')
+})
+
+test('formatLastTurn renders sections', () => {
+  const text = formatLastTurn({ userText: 'hi', assistantText: 'hello' })
+  assert.match(text, /【用户】/)
+  assert.match(text, /hi/)
+  assert.match(text, /【助手】/)
+  assert.match(text, /hello/)
+})