feat(coding): add conversation archive and first-message titles

tests/unit/coding-conversation-title.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, it } from 'vitest';
+import { firstMessageTitle } from '../../electron/coding-runtime/conversation-title';
+import type { ConversationMessageNode } from '../../shared/coding-conversation-contracts';
+
+function message(text: string, overrides: Partial<ConversationMessageNode> = {}): ConversationMessageNode {
+  return { kind: 'message', id: 'user', role: 'user', status: 'complete',
+    blocks: [{ kind: 'text', id: 'text', status: 'complete', text }], ...overrides };
+}
+
+describe('first user message title', () => {
+  it('uses the first line, collapses whitespace, and bounds long text by characters', () => {
+    expect(firstMessageTitle(message('  做一个   登录页\n支持短信登录'))).toBe('做一个 登录页');
+    expect(firstMessageTitle(message('🦊'.repeat(40)))).toBe('🦊'.repeat(32));
+  });
+  it('ignores optimistic, assistant, command and empty content', () => {
+    expect(firstMessageTitle(message('draft', { status: 'optimistic' }))).toBeNull();
+    expect(firstMessageTitle(message('reply', { role: 'assistant' }))).toBeNull();
+    expect(firstMessageTitle(message('/compact'))).toBeNull();
+    expect(firstMessageTitle(message('  '))).toBeNull();
+  });
+  it('names image-only conversations without inspecting the attachment', () => {
+    expect(firstMessageTitle(message('', { blocks: [{ kind: 'image', id: 'img', attachmentId: 'attachment', mime: 'image/png' }] }))).toBe('附件对话');
+  });
+});