Set version to 26.03.01.1 (YY.MM.DD.iteration format)

pubspec: 26.03.01+1 (Flutter uses + to separate versionName/versionCode)
Update checker combines version + buildNumber → "26.03.01.1" for
comparison against Forgejo release tags in the same format.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pubspec.yaml

@@ -2,7 +2,7 @@ name: fabled_app
 description: "FabledAssistant mobile client for Android."
 publish_to: 'none'
 
-version: 1.0.0+1
+version: 26.03.01+1
 
 environment:
   sdk: ^3.11.0