feat: ship v1.2.0 Wave 1 foundation with book settings, chapter management, and focus mode

Deliver schema v9, book/chapter IPC extensions, BookSettingsTab, chapter meta/tags,
AI session menu, focus mode and TTS, template context enrich, and Wave 1 E2E coverage.

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

src/main/ipc/handlers/book.handler.ts

@@ -1,6 +1,8 @@
-import { ipcMain } from 'electron'
+import { ipcMain, dialog, app } from 'electron'
+import { copyFileSync, mkdirSync } from 'fs'
+import { extname, join } from 'path'
 import { IPC } from '../../../shared/ipc-channels'
-import type { BookMeta, CreateBookParams } from '../../../shared/types'
+import type { CreateBookParams, UpdateBookMetaParams } from '../../../shared/types'
 import { BookRegistryService } from '../../services/book-registry'
 import type { WritingSessionService } from '../../services/writing-session.service'
 import { wrap } from '../result'
@@ -35,17 +37,24 @@ export function registerBookHandlers(
 
   ipcMain.handle(
     IPC.BOOK_UPDATE_META,
-    (
-      _event,
-      {
-        bookId,
-        ...patch
-      }: {
-        bookId: string
-        lastChapterId?: string | null
-        lastOpenedAt?: string
-        status?: BookMeta['status']
-      }
-    ) => wrap(() => registry.updateMeta(bookId, patch))
+    (_event, { bookId, ...patch }: { bookId: string } & UpdateBookMetaParams) =>
+      wrap(() => registry.updateMeta(bookId, patch))
+  )
+
+  ipcMain.handle(IPC.BOOK_PICK_COVER, (_event, { bookId }: { bookId: string }) =>
+    wrap(async () => {
+      const { canceled, filePaths } = await dialog.showOpenDialog({
+        filters: [{ name: 'Images', extensions: ['jpg', 'jpeg', 'png', 'webp'] }],
+        properties: ['openFile']
+      })
+      if (canceled || !filePaths[0]) return null
+      const src = filePaths[0]
+      const ext = extname(src).toLowerCase() || '.jpg'
+      const coversDir = join(app.getPath('userData'), 'covers')
+      mkdirSync(coversDir, { recursive: true })
+      const dest = join(coversDir, `${bookId}${ext}`)
+      copyFileSync(src, dest)
+      return registry.updateMeta(bookId, { coverPath: dest })
+    })
   )
 }