Lagrange 2.1.1 issue #367 test build

This prerelease is for testing the BookOrbit PDF page-position fix reported in issue #367.

Fix under test

• Normalize BookOrbit's one-based PDF page numbers before restoring the reader position, so the first PDF page opens as page 1 rather than page 2.

Test request

Please install the APK and test several PDFs through BookOrbit. In particular, verify that:

• a newly opened PDF starts on page 1;
• both paginated and continuous modes report the expected page number;
• reopening a PDF restores the expected page on the BookOrbit web reader and in Lagrange Reader.

This is a prerelease test build, not a stable release.