chore: clear prerelease marker after v2.1.0 stable release

v2.1.0 has been promoted to stable from the verified v2.1.0-beta.3
build; the source no longer needs to self-report as a prerelease.

Author: overwrite00

CHANGELOG.md

@@ -9,7 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [2.1.0] - 2026-07-29
 
-Focused on advanced privacy export, full OCR support for scanned PDFs, and new Lite/Full release variants. Validated through the 2.1.0-beta.1/beta.2 prereleases before this stable release; only the final stable version gets its own heading here.
+Focused on advanced privacy export, full OCR support for scanned PDFs, and new Lite/Full release variants. Validated through the 2.1.0-beta.1/beta.2/beta.3 prereleases before this stable release, promoted from `v2.1.0-beta.3` without rebuilding; only the final stable version gets its own heading here.
 
 ### ✨ Added
 

NullifyPDF.py

@@ -57,7 +57,7 @@
 )
 
 __version__ = "2.1.0"
-__version_prerelease__ = "beta.3"
+__version_prerelease__ = ""
 APP_VERSION = (
     f"{__version__}-{__version_prerelease__}"
     if __version_prerelease__