- Re-enable 16 previously skipped Playwright E2E tests that now pass
- Fix test setup issues that were causing flakiness
## Changes
- **task/task.spec.ts** (8 tests): kanban navigation, description
editing, assignees, labels, due dates
- **task/overview.spec.ts** (4 tests): task ordering, due date handling
- **user/settings.spec.ts** (2 tests): avatar upload, name update
- **user/login.spec.ts** (2 tests): bad password error, redirect after
login
## Key fixes
- Kanban view tests now properly create `TaskBucket` entries so tasks
appear in the kanban board
- Avatar upload test uses the API directly to avoid `canvas.toBlob()`
issues in headless browser environments
- Login redirect test no longer uses the shared `login()` helper that
expected redirect to `/`