Universal data portability: CSV import/export, clearer backup labels, alarm fixes

[nufuturepro]

Universal data portability, supply tracking, and alarm fixes

Three areas in a single commit:

1. Data portability

• JSON export/import: full-fidelity backups (all item types, taken history, supply settings); import merges by ID and never duplicates or destroys existing data.
• CSV export/import: spreadsheet-friendly, with the three supply columns; older CSVs without them import unchanged.

2. Supply tracking & widget

• Per-medication supply tracker (doses left / refill size / low threshold) with a card badge that turns red at the threshold.
• Taking or un-taking a dose updates stock through every path: in-app, notification action, and Wear.
• One-time low-supply notification per entry (own high-priority channel), auto-cancelled on refill, edit, delete, or un-take; re-evaluated on app start, boot, and import.
• Lowest-supply home-screen widget, refreshed on every data save.

3. Taken-history hardening (the core of this update)

Every path that could silently destroy a logged dose is fixed, with the rules extracted into a pure MedUpdatePlanner covered by an 18-test JVM suite:

• No-op guard: saving the editor without changes no longer deletes and recreates the entry (which reset takenHistory).
• Supply-only edits apply in place across the whole group — no entry recreation, no history loss, no fragmentation.
• Sibling-slot preservation: editing one dose slot of a multi-dose med no longer deletes the other slots and their history; a changed time carries its history to the new time.
• Range edits ("only this event" / "all following" / date range) no longer wipe takenHistory and no longer leave phantom history-free schedule fragments; history is trimmed to the window each fragment actually covers.
• Illness renames keep their notes.
• Stats: adherence counts each medication+time slot once per day, so legacy duplicate fragments can't deflate streaks.
• Alarm resilience: all dose alarms are re-armed on every app start (previously lost after a force-stop until an unrelated edit).

The importer also un-tracks the accidentally committed local.properties.