Merge pull request #12 from Tae-uni/feat/11-swagger-api-docs

:pencil: add OpenAPI spec for all the endpoints

:sparkles: set up Swagger UI with base OpenAPI config

:bug: vote expiration check and bcrypt import cleanup

:recycle: (client) split SyncData into payload and view types

Merge pull request #10 from Tae-uni/feat/8-sync-expiration

:sparkles: (client) handle SYNC_EXPIRED error on Sync detail page

:sparkles: (client) add optional expiration field to Sync creation form

:sparkles: (server) add weekly Cron job to clean up expired Syncs

:sparkles: (server) add Sync expiration with SYNC_EXPIRED handling

Merge pull request #7 from Tae-uni/feat/5-delete-sync

:sparkles: (client) implement Sync delete page

:sparkles: (server) implement Sync delete endpoint

:sparkles: (client) add form validation to create Sync

Merge pull request #6 from Tae-uni/feat/1-update-sync