fix(web,api): lecteur — worker pdf.js dédié, shell commun et préférences par livre

Régression worker PDF : le worker pdf.js est désormais instancié une
seule fois via un port dédié (?worker&url) et reconfiguré à chaque
montage, au lieu d'un workerSrc recalculé qui cassait le rendu.

- ReaderShell : chrome commun aux lecteurs (toolbar, zones de tap,
  statut) et contrat ReaderControls pour EPUB/PDF/CBZ
- préférences de lecture par livre (mode horizontal/vertical, fit) :
  table reader_preferences + migrations idempotentes, module API,
  DTO partagés, client web avec fallback localStorage hors-ligne

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/web/src/api/client.ts

@@ -26,9 +26,10 @@ import {
   mockProgress,
   mockUser
 } from "./mockData";
-import type { CbzPagesDto, ContinueItem, Session } from "./types";
+import type { CbzPagesDto, ContinueItem, ReaderPreferencesDto, Session } from "./types";
 
 const API_BASE = import.meta.env.VITE_API_BASE_URL ?? "";
+const READER_PREFERENCES_PREFIX = "readabook:reader-preferences:";
 
 type RequestOptions = RequestInit & {
   fallback?: unknown;
@@ -111,6 +112,30 @@ function queryString(query: Partial<BookQueryDto>): string {
   return value ? `?${value}` : "";
 }
 
+function readerPreferencesKey(bookId: number): string {
+  return `${READER_PREFERENCES_PREFIX}${bookId}`;
+}
+
+function readLocalReaderPreferences(bookId: number): ReaderPreferencesDto {
+  if (typeof localStorage === "undefined") return { mode: "horizontal", fit: "page" };
+  const raw = localStorage.getItem(readerPreferencesKey(bookId));
+  if (!raw) return { mode: "horizontal", fit: "page" };
+  try {
+    const parsed = JSON.parse(raw) as Partial<ReaderPreferencesDto>;
+    return {
+      mode: parsed.mode === "vertical" ? "vertical" : "horizontal",
+      fit: parsed.fit === "width" ? "width" : "page"
+    };
+  } catch {
+    return { mode: "horizontal", fit: "page" };
+  }
+}
+
+function writeLocalReaderPreferences(bookId: number, preferences: ReaderPreferencesDto): void {
+  if (typeof localStorage === "undefined") return;
+  localStorage.setItem(readerPreferencesKey(bookId), JSON.stringify(preferences));
+}
+
 export const api = {
   async session(): Promise<Session> {
     try {
@@ -176,6 +201,31 @@ export const api = {
       fallback: { bookId, ...input, updatedAt: new Date().toISOString() }
     });
   },
+  async readerPreferences(bookId: number): Promise<ReaderPreferencesDto> {
+    try {
+      const preferences = await request<ReaderPreferencesDto>(`/reader/preferences/${bookId}`, {
+        fallback: readLocalReaderPreferences(bookId)
+      });
+      writeLocalReaderPreferences(bookId, preferences);
+      return preferences;
+    } catch (error) {
+      if (error instanceof ApiFallbackError) return error.fallback as ReaderPreferencesDto;
+      return readLocalReaderPreferences(bookId);
+    }
+  },
+  async saveReaderPreferences(bookId: number, input: ReaderPreferencesDto): Promise<ReaderPreferencesDto> {
+    writeLocalReaderPreferences(bookId, input);
+    try {
+      return await request<ReaderPreferencesDto>(`/reader/preferences/${bookId}`, {
+        method: "PUT",
+        body: JSON.stringify(input),
+        fallback: input
+      });
+    } catch (error) {
+      if (error instanceof ApiFallbackError) return error.fallback as ReaderPreferencesDto;
+      return input;
+    }
+  },
   async continueReading(): Promise<ContinueItem[]> {
     return request<ContinueItem[]>("/progress/continue", { fallback: mockContinue });
   },