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>

public/locales/en/translation.json

@@ -457,5 +457,49 @@
   "submission.setDefault": "Set as default",
   "inspiration.selectBook": "Link to book",
   "inspiration.saved": "Idea saved",
-  "inspiration.noBooks": "Create a book first to save ideas"
+  "inspiration.noBooks": "Create a book first to save ideas",
+  "bookSettings.title": "Book settings",
+  "bookSettings.synopsis": "Synopsis",
+  "bookSettings.cover": "Cover",
+  "bookSettings.pickCover": "Choose cover image",
+  "bookSettings.noCover": "Not set",
+  "bookSettings.alwaysShowCockpit": "Show cockpit on every open",
+  "bookSettings.dangerZone": "Danger zone",
+  "bookSettings.deleteBook": "Delete this book",
+  "bookSettings.deleteConfirm": "Delete \"{{name}}\"? This cannot be undone.",
+  "volume.rename": "Rename volume",
+  "volume.renamePrompt": "Volume name",
+  "volume.editDescription": "Edit description",
+  "volume.descriptionPrompt": "Volume description",
+  "volume.delete": "Delete volume",
+  "volume.deleteConfirm": "Delete volume \"{{name}}\"?",
+  "volume.deleteHasChapters": "Cannot delete a volume that still has chapters",
+  "chapter.delete": "Delete chapter",
+  "chapter.deleteConfirm": "Delete chapter \"{{title}}\"?",
+  "chapterMeta.title": "Chapter metadata",
+  "chapterMeta.open": "Meta",
+  "chapterMeta.summary": "Summary",
+  "chapterMeta.storyTime": "Story time",
+  "chapterMeta.wordThreshold": "Word count threshold",
+  "chapterMeta.tags": "Tags",
+  "chapterMeta.tagPlaceholder": "Enter tag",
+  "chapterMeta.addTag": "Add",
+  "chapterMeta.publishedAt": "Published {{date}}",
+  "ai.session.rename": "Rename session",
+  "ai.session.renamePrompt": "Session title",
+  "ai.session.archive": "Archive",
+  "ai.session.unarchive": "Unarchive",
+  "ai.session.export": "Export",
+  "ai.session.exportMd": "Markdown (.md)",
+  "ai.session.exportTxt": "Plain text (.txt)",
+  "ai.session.delete": "Delete session",
+  "ai.session.deleteConfirm": "Delete session \"{{title}}\"?",
+  "ai.session.active": "Active",
+  "ai.session.archived": "Archived",
+  "focus.toggle": "Focus mode",
+  "focus.exit": "Exit focus",
+  "tts.started": "Reading aloud",
+  "tts.stopped": "Stopped reading",
+  "tts.noText": "Nothing to read",
+  "home.exportAllWave2": "Bulk export coming in a later release"
 }