new importer

[lindesvard]

Summary by CodeRabbit

• New Features

  • Event import flow for Umami and Mixpanel with provider-specific import modal and project mappings
  • New "Imports" settings tab showing import history, live progress, status badges, retry/delete actions and detailed config view

• UI

  • Badge component gains success/warning/info variants
  • Project mapper UI for mapping source→destination projects; date picker caption offers dropdown layout

• Chores

  • Database and build updates to support import tracking and background import processing