fix(auth): prevent AuthNotifier auto-dispose causing theme toggle logout

Applied @persistentRiverpod annotation to AuthNotifier so it persists
for app lifetime. Previously, theme changes could trigger AuthProvider
rebuild via auto-dispose, causing AsyncLoading state and auth issues.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.1.15] - 2026-01-05
+
+### Fixed
+- Theme toggle causing auth issues due to AuthNotifier auto-dispose
+  - Applied `@persistentRiverpod` annotation to AuthNotifier
+  - AuthProvider now persists for app lifetime, preventing rebuild on theme change
+
 ## [1.1.14] - 2026-01-04
 
 ### Fixed