feat: ship v1.1.0 writer toolkit with templates, import, export, and inspiration capture

Implement chapter templates, txt/md/docx import, submission export presets, and global inspiration shortcut. Split import handlers into a separate main bundle and fix EditorLayout setTarget loop that broke E2E.

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

tests/main/chapter-splitter.test.ts

@@ -0,0 +1,31 @@
+import { describe, it, expect } from 'vitest'
+import { splitPlainText } from '../../src/main/lib/chapter-splitter'
+
+const SAMPLE = `前言内容
+
+# 第一章 开端
+
+第一段正文。
+
+# 第二章 发展
+
+第二段正文。
+
+# 第三章 结局
+
+第三段正文。`
+
+describe('chapter-splitter', () => {
+  it('UT-IMPORT-01: auto split finds 3 chapters', () => {
+    const parts = splitPlainText(SAMPLE, 'auto')
+    expect(parts).toHaveLength(3)
+    expect(parts[0]!.title).toContain('第一章')
+    expect(parts[2]!.title).toContain('第三章')
+  })
+
+  it('paragraph mode splits by blank lines', () => {
+    const text = '标题一\n\n正文一\n\n标题二\n\n正文二'
+    const parts = splitPlainText(text, 'paragraph')
+    expect(parts.length).toBeGreaterThanOrEqual(2)
+  })
+})