Fix daily summary to display real activity counts and add medicine tracker

## Backend Changes
- Update tracking.service.ts getDailySummary to calculate actual counts
- Import ActivityType enum for proper type comparisons
- Calculate feedingCount, sleepTotalMinutes, diaperCount, medicationCount
- Sleep duration now correctly calculated from startedAt/endedAt timestamps

## Frontend API Changes
- Add medicationCount to DailySummary interface
- Extract endTime from metadata and send as endedAt to backend
- Enables proper sleep duration tracking with start/end times

## Homepage Updates
- Add Medicine and Activities quick action buttons
- Update summary grid from 3 to 4 columns (responsive layout)
- Add medication count display with MedicalServices icon
- Improve grid responsiveness (xs=6, sm=3)
- Replace Analytics button with Activities button

## New Activities Page
- Create /activities page to show recent activity history
- Display last 7 days of activities with color-coded icons
- Show smart timestamps (Today/Yesterday/date format)
- Activity-specific descriptions (feeding amount, sleep duration, etc.)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

maternal-web/lib/api/tracking.ts

@@ -27,6 +27,7 @@ export interface DailySummary {
   feedingCount: number;
   sleepTotalMinutes: number;
   diaperCount: number;
+  medicationCount: number;
   activities: Activity[];
 }
 
@@ -68,12 +69,18 @@ export const trackingApi = {
   // Create a new activity
   createActivity: async (childId: string, data: CreateActivityData): Promise<Activity> => {
     // Transform frontend data structure to backend DTO format
-    const payload = {
+    const payload: any = {
       type: data.type,
       startedAt: data.timestamp, // Backend expects startedAt, not timestamp
       metadata: data.data,        // Backend expects metadata, not data
       notes: data.notes,
     };
+
+    // Extract endTime from metadata and set as endedAt (for sleep tracking)
+    if (data.data?.endTime) {
+      payload.endedAt = data.data.endTime;
+    }
+
     const response = await apiClient.post(`/api/v1/activities?childId=${childId}`, payload);
     const activity = response.data.data.activity;
     // Transform backend response to frontend format