fix(ebook-reader): Replace ReflowableBook with UniversalReader type system

BREAKING CHANGE: Unify ebook reader type system to match actual data structures

Problem:
- ReflowableBook type had direct properties (spine, resources, toc, metadata)
- UniversalReader wraps EbookCIF in cif property with runtime state
- Type mismatch caused unsafe 'as any' casts and runtime errors
- Two conflicting UniversalReader definitions existed (reader-shell vs reader-context)

Root Cause:
- Parsers return EbookCIF (nested structure)
- ReflowableBook expected flat structure
- Code mixed both approaches causing confusion

Changes:

Type System Updates:
- Replace all ReflowableBook references with UniversalReader
- Remove duplicate UniversalReader definition in reader-context.ts
- Import UniversalReader from canonical source (reader-shell.ts)
- Update all function signatures across reflowable module

Property Access Patterns:
- book.cif.spine instead of book.spine
- book.cif.resources instead of book.resources
- book.cif.toc instead of book.toc
- book.cif.metadata instead of book.metadata

Fixed Modules:
- reader-shell.ts: UniversalReader object construction
- reader-context.ts: Remove duplicate interface, import from reader-shell
- reader-navigation.ts: Remove unsafe type casts, fix property access
- reader-services.ts: Align with UniversalReader structure
- reflowable/navigation.ts: Update all navigation function signatures
- reflowable/progress-tracker.ts: Update tracker function signatures
- reflowable/parser.ts: Return UniversalReader with proper structure
- reflowable/page-calculator.ts: Update calculation function signatures
- reflowable/ebook/search.ts: Fix property access patterns
- types/reader.d.ts: Remove duplicate type definitions

Impact:
- ✅ Type-safe throughout ebook reader
- ✅ Matches actual data structures from parsers
- ✅ No more unsafe type casts
- ✅ Single source of truth for UniversalReader
- ✅ Aligns with EbookCIF format from API/parsers

Files changed: 10
Lines changed: +320, -180

web/src/reader/formats/reflowable/parser.ts

@@ -1,51 +1,113 @@
 // Import types and existing parsers
-import type { ReflowableBook, SpineItem, TOCItem } from "./types";
+import type { TOCItem } from "./types";
 import { parseEPUB } from "../../parsers/epub-parsers";
 import { parseFB2 } from "../../parsers/fb2-parser";
 import { parseTXT } from "../../parsers/txt-parser";
 import { parseHTML } from "../../parsers/html-parser";
+import { UniversalReader } from "../../reader-shell";
 
 // Parse any reflowable format
 export async function parseReflowable(
   file: File,
   format: "epub" | "fb2" | "txt" | "html",
-): Promise<ReflowableBook> {
+): Promise<UniversalReader> {
   switch (format) {
-    case "epub":
-      return await parseEPUB(file);
-    case "fb2":
-      return await parseFB2(file);
-    case "txt":
-      return await parseTXT(file);
-    case "html":
-      return await parseHTML(file);
+    case "epub": {
+      const cif = await parseEPUB(file); // Get EbookCIF
+      return {
+        // Wrap in UniversalReader structure
+        type: "ebook",
+        cif, // ← The EbookCIF goes here
+        currentSpineIndex: 0,
+        currentPage: 1,
+        pagination: null,
+        position: {
+          currentPage: 1,
+          spineIndex: 0,
+          localPageIndex: 0,
+          cfi: "",
+          progress: 0,
+        },
+      };
+    }
+    case "fb2": {
+      const cif = await parseFB2(file);
+      return {
+        type: "ebook",
+        cif,
+        currentSpineIndex: 0,
+        currentPage: 1,
+        pagination: null,
+        position: {
+          currentPage: 1,
+          spineIndex: 0,
+          localPageIndex: 0,
+          cfi: "",
+          progress: 0,
+        },
+      };
+    }
+    case "txt": {
+      const cif = await parseTXT(file);
+      return {
+        type: "ebook",
+        cif,
+        currentSpineIndex: 0,
+        currentPage: 1,
+        pagination: null,
+        position: {
+          currentPage: 1,
+          spineIndex: 0,
+          localPageIndex: 0,
+          cfi: "",
+          progress: 0,
+        },
+      };
+    }
+    case "html": {
+      const cif = await parseHTML(file);
+      return {
+        type: "ebook",
+        cif,
+        currentSpineIndex: 0,
+        currentPage: 1,
+        pagination: null,
+        position: {
+          currentPage: 1,
+          spineIndex: 0,
+          localPageIndex: 0,
+          cfi: "",
+          progress: 0,
+        },
+      };
+    }
     default:
       throw new Error(`Unsupported reflowable format: ${format}`);
   }
 }
 
 // Validate parsed book data
-export function validateBook(book: ReflowableBook): boolean {
-  return book.spine.length > 0 && book.metadata.title !== "";
+export function validateBook(book: UniversalReader): boolean {
+  return book.cif.spine.length > 0 && book.cif.metadata.title !== "";
 }
 
 // Get book title
-export function getBookTitle(book: ReflowableBook): string {
-  return book.metadata.title || "Untitled";
+export function getBookTitle(book: UniversalReader): string {
+  return book.cif.metadata.title || "Untitled";
 }
 
 // Get book author
-export function getBookAuthor(book: ReflowableBook): string {
-  return book.metadata.author || "Unknown";
+export function getBookAuthor(book: UniversalReader): string {
+  return book.cif.metadata.author || "Unknown";
 }
 
 // Get total spine count
-export function getSpineCount(book: ReflowableBook): number {
-  return book.spine.length;
+export function getSpineCount(book: UniversalReader): number {
+  return book.cif.spine.length;
 }
 
 // Get TOC as flat list
-export function getFlatTOC(book: ReflowableBook): TOCItem[] {
+export function getFlatTOC(book: UniversalReader): TOCItem[] {
   const flat: TOCItem[] = [];
 
   function traverse(items: TOCItem[]) {
@@ -57,6 +119,6 @@ export function getFlatTOC(book: ReflowableBook): TOCItem[] {
     }
   }
 
-  traverse(book.toc);
+  traverse(book.cif.toc);
   return flat;
 }