Add a private provider-neutral SQLite WAL cache with transactional migrations, retained raw payloads and tombstones, per-window opaque checkpoints, and reserved outbox/conflict tables.
Verify migrations, permissions, identity invariants, concurrent access, atomic pull-page rollback, and future-schema rejection with deterministic tests. No OAuth, networking, secrets, or Graph synchronization is included yet.
Add a Monday-default --week-start option for every weekday and carry it through domain layout, full and compact rendering, event query windows, print mode, and the interactive TUI.
Preserve byte-compatible Monday output and cover rotated headers, spill dates, invalid input, sanitizer behavior, and live terminal restoration.
