fix: 修复体重管理模块的导航功能

- 修正体重卡片的导航链接，确保用户能够正确访问体重管理页面
- 优化导航逻辑，提升用户体验

.cursor/plans/weight-management-implementation-7f3662cc.plan.md

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+<!-- 7f3662cc-b5d9-4275-ae1f-e41be47f9b08 4c210450-6acb-41bf-b5dd-6181ee548ec4 -->
+# Weight Management Implementation Plan
+
+## Overview
+
+This document outlines the implementation of a comprehensive weight management system in the WeightComponent at `campus_health_app/frontend/campus-health-app/src/app/modules/weight/weight.component.ts`. All features will be implemented in a single component using ECharts for visualizations, with data persisted in localStorage and synced with backend API.
+
+## Implementation Steps
+
+### 1. Dependencies Installation
+
+Install required packages:
+
+- `echarts`: ^5.4.3 (charting library)
+- `ngx-echarts`: ^17.0.0 (Angular wrapper for ECharts)
+
+### 2. Data Models Enhancement
+
+Extend existing `WeightRecord` interface and add new interfaces:
+
+- **WeightRecord**: Add fields for `measurementTime`, `measurementCondition` (空腹/餐后), `notes`, `tags` (关键节点标记)
+- **WeightGoal**: `targetWeight`, `targetBodyFat`, `targetDate`, `startWeight`, `startDate`, `weeklyTarget`
+- **AnomalyAlert**: `type`, `severity`, `message`, `detectedDate`
+
+### 3. Component Structure
+
+#### Core Features Implementation:
+
+**A. Data Collection Module**
+
+- Modal/Dialog component for weight input with fields:
+  - Weight (kg), Body Fat (%), Muscle Mass (kg)
+  - Measurement time picker, Condition selector (空腹/餐后)
+  - Notes textarea, Tag selector for milestones
+- Validation: weight range 30-200kg, body fat 5-60%
+- Save to localStorage immediately, queue for backend sync
+
+**B. Goal Management Module**
+
+- Goal setting dialog with:
+  - Target weight and body fat percentage inputs
+  - Target date picker with minimum date validation
+  - Auto-calculate weekly target based on time difference
+  - Display predicted completion date based on current trend
+- Store in localStorage under `weightGoal` key
+- Backend sync on save
+
+**C. Anomaly Detection Engine**
+
+- Simple threshold-based detection:
+  - Rapid weight change: >2kg/week or >0.5kg/day
+  - Body fat anomaly: body fat% increases while weight decreases
+  - Missing data: >7 days without measurement
+  - Extreme values: outside personalized ±5% range
+- Generate alerts with severity levels (info/warning/danger)
+- Display in dedicated alert section at bottom
+
+**D. Multi-dimensional Filtering**
+
+- Time period filters: 7天/30天/90天/全部
+- Date range picker for custom periods
+- Measurement condition filter: 全部/空腹/餐后
+- Tag-based filtering for milestone events
+- Comparison mode: compare current period vs previous period
+
+### 4. Visualization Charts (ECharts Configuration)
+
+**Chart 1: Weight Trend Line Chart (Primary, 50% height)**
+
+```typescript
+// Three lines: actual weight (blue), target weight (red), planned trend (gray dashed)
+// X-axis: time with custom markers for tagged events
+// Y-axis: weight in kg
+// Tooltip: show date, weight, body fat, measurement condition
+// DataZoom: enable for mobile pinch-to-zoom
+// MarkLine: for goal weight and start weight
+// MarkPoint: for milestone events (开始运动日, 目标调整日)
+```
+
+**Chart 2: Weekly/Monthly Weight Change Bar Chart**
+
+```typescript
+// Calculate weight delta per week/month
+// Green bars for weight loss (negative values)
+// Red bars for weight gain (positive values)
+// Label on top of each bar showing exact value (e.g., "-0.6kg")
+// Toggle between weekly/monthly view
+```
+
+**Chart 3: Weight vs Body Fat Scatter Plot (Right side small chart)**
+
+```typescript
+// X-axis: weight (kg), Y-axis: body fat (%)
+// Each point represents one measurement
+// Color gradient based on date (older = lighter)
+// Reference lines showing ideal trend (down-left diagonal)
+// Tooltip showing date and values
+```
+
+**Chart 4: Goal Progress Ring Chart (Top-right floating)**
+
+```typescript
+// Gauge/Pie chart showing progress percentage
+// Inner text: "已减 3kg / 目标 5kg"
+// Outer ring: progress arc (60% filled)
+// Bottom text: "还需减 2kg，预计 11月30日完成"
+// Color: green if on track, yellow if slow, red if off track
+```
+
+**Chart 5: Summary Stats Cards (Above trend chart)**
+
+- Current weight, Weight change from start, Days tracked
+- Average weekly change, Body fat change, Goal completion ETA
+
+### 5. Layout Structure (Mobile-first)
+
+```
+┌─────────────────────────────────────┐
+│ Header: 体重管理 [录入] [目标设置]    │
+├─────────────────────────────────────┤
+│ Summary Cards (3 cards in row)      │
+├──────────────────────┬──────────────┤
+│                      │  Goal Ring   │
+│  Weight Trend Chart  │  (Floating)  │
+│  (50% height)        │              │
+│                      │              │
+├──────────────────────┴──────────────┤
+│ Filter Bar: [7天][30天][90天][自定义]│
+├─────────────────────────────────────┤
+│ Weekly/Monthly Change Bar Chart     │
+├──────────────────────────────────────┤
+│ Weight vs Body Fat Scatter Plot     │
+├─────────────────────────────────────┤
+│ Anomaly Alerts & Suggestions        │
+└─────────────────────────────────────┘
+```
+
+### 6. Data Persistence Strategy
+
+**LocalStorage Structure:**
+
+```typescript
+{
+  weightRecords: WeightRecord[],
+  weightGoal: WeightGoal,
+  pendingSync: { records: [], goal: null },
+  lastSyncTime: timestamp
+}
+```
+
+**Backend Sync Logic:**
+
+- On component init: fetch latest data from backend, merge with local
+- On data change: save to localStorage immediately, add to pendingSync queue
+- Periodic sync (every 5 minutes): POST pendingSync items to backend
+- Conflict resolution: backend timestamp wins
+- Offline support: queue operations, sync when online
+
+### 7. Services & State Management
+
+Create `WeightDataService`:
+
+- CRUD operations for weight records
+- Goal management methods
+- Sync coordinator between localStorage and backend
+- Observable streams for reactive UI updates
+
+### 8. Mobile Optimization
+
+- Touch-friendly chart interactions (touch to show tooltip)
+- Responsive grid layout (charts stack vertically on small screens)
+- Optimize chart rendering for mobile performance
+- Use virtual scrolling for record list if >100 items
+
+### 9. Key Implementation Details
+
+**Planned Trend Line Calculation:**
+
+```typescript
+// Linear interpolation from start weight to target weight
+planWeight = startWeight - (daysElapsed / totalDays) * totalWeightToLose
+```
+
+**Anomaly Detection Algorithm:**
+
+```typescript
+// Check last 7 days for rapid changes
+if (Math.abs(weeklyChange) > 2) {
+  alert = { type: 'rapid_change', severity: 'warning', message: '...' }
+}
+```
+
+**ETA Calculation:**
+
+```typescript
+// Based on average weekly change over last 4 weeks
+avgWeeklyChange = sum(last4WeeksChanges) / 4
+weeksRemaining = remainingWeight / Math.abs(avgWeeklyChange)
+eta = new Date(now + weeksRemaining * 7 * 24 * 60 * 60 * 1000)
+```
+
+## File Structure
+
+```
+campus_health_app/docs/
+  └── weight-management-implementation.md  (this document)
+
+campus_health_app/frontend/campus-health-app/src/app/
+  ├── modules/weight/
+  │   ├── weight.component.ts (main implementation)
+  │   ├── weight.component.html (template with all charts)
+  │   ├── weight.component.scss (mobile-first responsive styles)
+  │   └── models/
+  │       └── weight.models.ts (data interfaces)
+  └── services/
+      └── weight-data.service.ts (data management & sync)
+```
+
+## Technical Specifications
+
+- **Framework**: Angular 17+ (standalone components)
+- **Charts**: ECharts 5.4.3 via ngx-echarts
+- **Styling**: SCSS with mobile-first breakpoints
+- **Data Storage**: LocalStorage + REST API sync
+- **State Management**: RxJS Observables
+- **Type Safety**: Full TypeScript typing for all data models
+
+## API Endpoints (Expected Backend)
+
+```
+GET    /api/weight/records?from={date}&to={date}
+POST   /api/weight/records
+PUT    /api/weight/records/{id}
+DELETE /api/weight/records/{id}
+GET    /api/weight/goal
+POST   /api/weight/goal
+PUT    /api/weight/goal
+```
+
+## Testing Considerations
+
+- Mock data for 90 days to test all visualizations
+- Test edge cases: no data, single data point, goal achieved
+- Test offline mode and sync recovery
+- Validate mobile touch interactions
+- Performance test with 365+ data points
+
+### To-dos
+
+- [ ] Create weight-management-implementation.md in campus_health_app/docs with complete implementation guide