Add TypeScript type definitions for reader feature

Define comprehensive TypeScript interfaces for reader functionality:
- Common Intermediate Format (CIF) for universal ebook representation
- Parser capabilities and format detection types
- Reader metadata and chapter structure interfaces
- Panel layout and dock system types
- Reading progress and settings interfaces
- Dictionary and search functionality types

These types provide the foundation for type-safe reader implementation
across all media types (ebook, comic, manga, pdf).

web/src/types/reader.d.ts

@@ -0,0 +1,203 @@
+// ============================================================
+// Common Intermediate Format (CIF) Types
+// Universal format for all reflowable ebooks after parsing
+// ============================================================
+
+interface EbookCIF {
+  // Universal metadata (all formats)
+  metadata: {
+    title: string;
+    author: string;
+    language: string;
+    publisher?: string;
+    isbn?: string;
+    coverImage?: Blob;
+  };
+
+  // Unified navigation structure
+  toc: TOCNode[];
+
+  // Content spine (reading order)
+  spine: SpineItem[];
+
+  // Resources (CSS, fonts, images)
+  resources: Map<string, Blob>;
+
+  // Progress tracking (minimal - backend handles detailed tracking)
+  locations: {
+    totalCharacters: number;
+    estimatedPages: number;
+  };
+}
+
+interface SpineItem {
+  id: string;
+  type: "html" | "image";
+  content: string;
+  properties?: string[];
+
+  // Minimal position info for UI
+  index: number;
+}
+
+interface TOCNode {
+  id: string;
+  title: string;
+  href: string;
+  children: TOCNode[];
+}
+
+// ============================================================
+// Parser Types (Procedural, not OOP)
+// ============================================================
+
+type ParserFormat =
+  | "epub"
+  | "fb2"
+  | "txt"
+  | "html"
+  | "mobi"
+  | "azw3"
+  | "docx"
+  | "rtf";
+
+interface ParserCapabilities {
+  canParse(mimeType: string, extension: string): boolean;
+  parse(file: Blob): Promise<EbookCIF>;
+  extractMetadata(file: Blob): Promise<Partial<EbookCIF["metadata"]>>;
+}
+
+// ============================================================
+// Reader Metadata (from API)
+// ============================================================
+
+interface ReaderMetadata {
+  media_item_id: string;
+  title: string;
+  author: string;
+  cover_image_path: string;
+  library_type: "ebook" | "comic" | "manga" | "pdf";
+  mime_type: string;
+  file_path: string;
+  chapter_metadata?: ChapterMetadata;
+  total_pages?: number;
+}
+
+// ============================================================
+// Other Shared Types
+// ============================================================
+
+interface ChapterMetadata {
+  chapters: Chapter[];
+}
+
+interface Chapter {
+  id: string;
+  title: string;
+  start_page: number;
+  page_count: number;
+}
+
+interface PanelData {
+  media_item_id: string;
+  page_number: number;
+  detection_method: "grid" | "ml" | "manual";
+  panels: Panel[];
+  updated_at: string;
+}
+
+interface Panel {
+  id: string;
+  x: number;
+  y: number;
+  width: number;
+  height: number;
+  reading_order: number;
+}
+
+interface ReadingSpeed {
+  words_per_minute: number;
+  pages_per_minute: number;
+  pages_read: number;
+  total_reading_minutes: number;
+  last_read_at: string;
+}
+
+interface DictionaryEntry {
+  word: string;
+  definition: string;
+  part_of_speech?: string;
+  example?: string;
+  etymology?: string;
+}
+
+interface ReaderSettings {
+  chrome_behavior: "auto-hide" | "always-visible" | "hide-on-scroll";
+  progress_mode: "pages" | "chapter" | "percentage" | "time-left";
+
+  chrome_theme: string;
+  reading_theme: "light" | "sepia" | "dark" | "night" | "high-contrast";
+
+  reading_font:
+    | "literata"
+    | "crimson"
+    | "source-serif"
+    | "eb-garamond"
+    | "libertinus"
+    | "noto-serif"
+    | "charis-sil"
+    | "ibm-plex";
+  font_size: number;
+  line_height: number;
+  margin_width: number;
+
+  tap_zone_size: number;
+  auto_scroll: boolean;
+  panel_zoom_enabled: boolean;
+
+  double_page_spread: boolean;
+  reading_direction: "ltr" | "rtl" | "vertical";
+
+  pdf_fit_mode: "fit-width" | "fit-page" | "fit-height" | "none";
+  pdf_zoom_level: number;
+  pdf_text_layer_enabled: boolean;
+  pdf_dual_page_mode: "auto" | "single" | "dual";
+  pdf_dual_page_threshold: number;
+  pdf_minimap_enabled: boolean;
+  pdf_outline_visible: boolean;
+  media_bookmarks_visible: boolean;
+
+  hardware_acceleration: boolean;
+
+  // Dockable panel layout configuration (per-user, media-type-aware)
+  panel_layout: PanelLayoutSettings;
+}
+
+interface PanelLayoutSettings {
+  // Per panel state: which side, visible, collapsed (window-shade), width
+  toc: PanelState;
+  settings: PanelState;
+  navigator: PanelState;
+  bookmarks: PanelState;
+
+  // Mobile override
+  mobile_nav_visible: boolean;
+}
+
+interface PanelState {
+  side: "left" | "right" | "hidden";
+  visible: boolean;
+  collapsed: boolean; // Window-shade: true = collapsed to title bar
+  width_px: number; // Panel width in pixels
+  order: number; // Order within the side
+  locked: boolean; // Lock toggle: prevents accidental drag/move
+  last_valid_side: "left" | "right" | "hidden"; // Snap-back target if dropped in invalid area
+}
+
+interface ProgressDisplay {
+  mode: "pages" | "chapter" | "percentage" | "time-left";
+  current: number;
+  total: number;
+  label?: string;
+  time_left?: string;
+}