feat: tc creds page changes and syncing fixes

[MabudAlam]

Summary

• Fixed sync-on-start not pulling new changes from CCSync — rewrote isNeededtoSyncOnStart to correctly branch between TaskReplica, TaskChampion, and legacy sync paths, with proper null-safety checks and error handling
• Replaced static sync icon with an animated spinning indicator — added a _SpinningIcon widget with RotationTransition so users get clear visual feedback that sync is in progress
• Added "Sync Completed" SnackBar across all sync paths (sync-on-start, replica refresh, TaskChampion refresh, and legacy synchronize) for consistent feedback
• Redesigned the TaskChampion credentials page — full-width styled "Save" button, added a CCSync section with description and "Open CCSync" link to taskwarrior-server.ccextractor.org, plus a self-hosted TaskChampion sync server link as an alternative

Changes

File	What changed
home_controller.dart	Rewrote isNeededtoSyncOnStart with correct sync-path branching, error handling, and SnackBar on completion
home_page_app_bar.dart	Added _SpinningIcon widget, added "Sync Completed" SnackBars, wrapped replica refresh in try/catch/finally
manage_task_champion_creds_view.dart	Restyled save button, added CCSync info section with external links, removed app bar info icon
english_sentences.dart	Changed saveCredentials label from "save credentials" to "Save"

[MabudAlam]

Hey @SGI-CAPP-AT2 , I made some UX and bug fixes . Please review it if needed or we can merge it .

[SGI-CAPP-AT2]

@pavel401 ,

I think this will match to the overall theme of Application

Should I push this change here? along with the translation of

                    'CCSync uses TaskChampion to sync your tasks '
                    'across multiple devices seamlessly. You also '
                    'get a web dashboard to manage your tasks from '
                    'any browser.',
                    'Or bring your own credentials from a self-hosted '
                    'TaskChampion sync server.',

[MabudAlam]

@pavel401 ,

I think this will match to the overall theme of Application

Should I push this change here? along with the translation of

                    'CCSync uses TaskChampion to sync your tasks '
                    'across multiple devices seamlessly. You also '
                    'get a web dashboard to manage your tasks from '
                    'any browser.',
                    'Or bring your own credentials from a self-hosted '
                    'TaskChampion sync server.',

Yes , thanks !