port: upstream PR #1342 - Book Info screen, richer metadata, safer controls

Ports upstream PR #1342 (feat: Add Book Info screen, richer metadata,
and safer file-browser controls) with mod-specific adaptations:

- Parse and cache series, seriesIndex, description from EPUB OPF
- Bump book.bin cache version to 6 for new metadata fields
- Add BookInfoActivity (new screen) accessible via Right button in FileBrowser
- Add ManageBook menu via Left button in FileBrowser (replaces upstream hidden delete)
- Guard all delete/archive actions with ConfirmationActivity (10 call sites)
- Add inputArmed gating to ConfirmationActivity to prevent accidental confirmation
- Safe deserialization: readString now returns bool with MAX_STRING_LENGTH guard
- Add series field to RecentBooksStore with JSON and binary serialization
- Add i18n keys: STR_BOOK_INFO, STR_AUTHOR, STR_SERIES, STR_FILE_SIZE, etc.

Made-with: Cursor

src/RecentBooksStore.h

@@ -6,6 +6,7 @@ struct RecentBook {
   std::string path;
   std::string title;
   std::string author;
+  std::string series;
   std::string coverBmpPath;
 
   bool operator==(const RecentBook& other) const { return path == other.path; }
@@ -31,11 +32,11 @@ class RecentBooksStore {
   static RecentBooksStore& getInstance() { return instance; }
 
   // Add a book to the recent list (moves to front if already exists)
-  void addBook(const std::string& path, const std::string& title, const std::string& author,
+  void addBook(const std::string& path, const std::string& title, const std::string& author, const std::string& series,
                const std::string& coverBmpPath);
 
   void updateBook(const std::string& path, const std::string& title, const std::string& author,
-                  const std::string& coverBmpPath);
+                  const std::string& series, const std::string& coverBmpPath);
 
   void removeBook(const std::string& path);