change default name to hash

Author: Henri93

README.md

@@ -9,7 +9,7 @@ A simple Python/FastAPI server for syncing reading progress across KOReader devi
 
 Don't want to deploy your own? 
 
-Just [create an account](https://www.null-space.xyz/reader) then set your KOReader or Readest app to use `https://api.null-space.xyz/reader` for progress sync.
+Just [create an account](https://www.null-space.xyz/reader) then set your KOReader or Readest app to use `https://api.null-space.xyz` for progress sync.
 
 > [!WARNING]
 > **Kindle Sync Timeout Issue**

svg_card.py

@@ -40,7 +40,7 @@ def render_progress_card(books: list["BookSummary"]) -> str:
     else:
         for i, book in enumerate(books):
             y_offset = header_height + (i * book_height) + 20
-            title = html.escape(book.label or book.filename or "Untitled")
+            title = html.escape(book.label or book.filename or book.canonical_hash)
             if len(title) > 40:
                 title = title[:37] + "..."