fix(auth): defer OIDC callback processing to post-frame

Wraps _processCallback() in addPostFrameCallback to avoid Riverpod
"Tried to modify a provider while the widget tree was building" error.

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

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

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.0.9] - 2026-01-04
+
+### Fixed
+- Fixed OIDC callback Riverpod state modification error
+  - Deferred callback processing to `addPostFrameCallback` to avoid modifying state during widget build
+
 ## [1.0.8] - 2026-01-04
 
 ### Changed

lib/routing/app_router.dart

@@ -286,7 +286,10 @@ class _OidcCallbackPageState extends ConsumerState<_OidcCallbackPage> {
   @override
   void initState() {
     super.initState();
-    _processCallback();
+    // Defer callback processing to avoid Riverpod state modification during build
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _processCallback();
+    });
   }
 
   Future<void> _processCallback() async {

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.8+1
+version: 1.0.9+1
 
 environment:
   sdk: ^3.10.4