The task-numbers slice added a UNIQUE index on tasks.number. Ui.Tests seed
TaskEntity rows directly instead of going through TaskRepository, so every row
kept the default Number = 0 and 31 tests failed with
'UNIQUE constraint failed: tasks.number'.
TasksIslandViewModel now runs a periodic tick that diffs the flat Items
collection against SQLite and patches properties in place (capped at 500
rows, sharing the Phase 1 delta sequence guard so it never overtakes a
fresher broadcast). Never rebuilds rows or triggers Regroup/LoadForList, so
it stays decoupled from the parallel Phase 2b virtualization work. The same
cadence now refreshes the long-lived Worktrees Overview, Log Visualizer, and
Merge Helper selection overlays; short-lived modals are untouched.
mika kuns