feat: Add package type support and per-intake takenBy (#89)

## Package Type Feature
- Add 'blister' and 'bottle' package types for medications
- Bottle type uses totalPills for capacity and looseTablets for current stock
- Blister type continues to use packCount/blistersPerPack/pillsPerBlister
- Add doseUnit field for flexible dosing (mg, ml, IU, etc.)
- Full UI support in medication form and detail modal

## Per-Intake TakenBy
- Move takenBy from medication level to individual intakes
- Each intake schedule can now be assigned to a different person
- Update scheduler-utils to handle per-intake takenBy
- Update SharedSchedule to filter by per-intake takenBy
- Backward compatible with existing medication data

## UI Improvements
- Add PasswordInput component with show/hide toggle
- Centralize stockThresholds in AppContext for consistent status display
- Fix SharedSchedule sync issues with per-intake takenBy
- Improve mobile editing experience

## Technical
- Add migrations 0004 and 0005 for schema changes
- Update all relevant tests (1064 tests passing)
- Maintain backward compatibility with ALTER migrations

frontend/src/components/index.ts

@@ -13,6 +13,7 @@ export type { MedicationAvatarProps } from "./MedicationAvatar";
 export { MedicationAvatar } from "./MedicationAvatar";
 export type { MobileEditModalProps } from "./MobileEditModal";
 export { MobileEditModal } from "./MobileEditModal";
+export { PasswordInput } from "./PasswordInput";
 export { default as ProfileModal } from "./ProfileModal";
 export type { ShareDialogProps } from "./ShareDialog";
 export { ShareDialog } from "./ShareDialog";