fix(web,api): UI fiche livre et lecteur — progression, locators EPUB/PDF, styles

- web: BookPage/ReaderPage enrichis, sauvegarde de progression lecteur
- web: locators EPUB/PDF normalisés (+ tests), EpubReader/PdfReader ajustés
- web: nginx et service worker ajustés
- api: progress — corrections contrôleur/service

Refs: #13

apps/web/public/sw.js

@@ -1,5 +1,5 @@
-const CACHE_NAME = "readabook-shell-v1";
-const SHELL = ["/", "/home", "/manifest.webmanifest", "/icons/readabook.svg"];
+const CACHE_NAME = "readabook-shell-v2";
+const SHELL = ["/", "/index.html", "/manifest.webmanifest", "/icons/readabook.svg"];
 
 self.addEventListener("install", (event) => {
   event.waitUntil(caches.open(CACHE_NAME).then((cache) => cache.addAll(SHELL)));
@@ -18,5 +18,19 @@ self.addEventListener("fetch", (event) => {
   if (event.request.method !== "GET" || ["/auth", "/admin", "/books", "/progress"].some((path) => url.pathname.startsWith(path))) {
     return;
   }
-  event.respondWith(fetch(event.request).catch(() => caches.match(event.request).then((hit) => hit || caches.match("/"))));
+  if (event.request.mode === "navigate") {
+    event.respondWith(
+      fetch(event.request)
+        .then((response) => {
+          const copy = response.clone();
+          caches.open(CACHE_NAME).then((cache) => cache.put("/index.html", copy));
+          return response;
+        })
+        .catch(() => caches.match("/index.html").then((hit) => hit || caches.match("/")))
+    );
+    return;
+  }
+  event.respondWith(
+    caches.match(event.request).then((hit) => hit || fetch(event.request))
+  );
 });