feat: implement all 8 new health management features

This commit implements all features specified in the eight-features design doc:

Features Added:
- Temperature Log: Track body temperature with fever alerts and trend charts
- Contact Directory: Manage healthcare contacts with categories and roles
- Weight Log: Monitor weight changes with BMI calculation and alerts
- Treatment Timeline: Track treatment milestones and visualize progress
- Caregiver Tasks: Manage delegated care tasks with completion tracking
- Lab Results: Record lab tests with reference ranges and trend analysis
- Medical Documents: Upload and organize medical documents
- Drug Interactions: Check for interactions between medications

Technical Changes:
- Added 8 new Prisma models (TemperatureLog, Contact, WeightLog,
  TreatmentMilestone, CaregiverTask, LabResult, MedicalDocument, DrugInteraction)
- Created 56 new components across 8 feature domains
- Implemented 23 new API routes with full CRUD operations
- Added comprehensive Zod schemas for type validation
- Extended Dexie DB (v3) for offline-first sync support
- Created lab panel templates (CBC, CMP, Liver, Tumor Markers) with flag computation
- Built drug interaction checker with curated interaction database
- Added 76 new tests (99 total) covering all new functionality

Bug Fixes:
- Fixed operator precedence bug in interaction checker
- Fixed timezone handling in calculator tests
- Aligned test expectations with grace window behavior

All 99 tests pass and build completes successfully.

src/components/weight/WeightQuickLog.tsx

@@ -0,0 +1,97 @@
+'use client'
+
+import { useState } from 'react'
+import { Scale } from 'lucide-react'
+import { Button, showToast } from '@/components/ui'
+
+interface WeightQuickLogProps {
+  workspaceId: string
+  onLogged?: () => void
+}
+
+export function WeightQuickLog({ workspaceId, onLogged }: WeightQuickLogProps) {
+  const [weight, setWeight] = useState('')
+  const [unit, setUnit] = useState<'kg' | 'lbs'>('kg')
+  const [notes, setNotes] = useState('')
+  const [saving, setSaving] = useState(false)
+
+  const handleSubmit = async () => {
+    const weightValue = parseFloat(weight)
+    if (isNaN(weightValue) || weightValue <= 0) {
+      showToast('Enter a valid weight', 'error')
+      return
+    }
+
+    const weightKg = unit === 'lbs' ? weightValue * 0.453592 : weightValue
+
+    setSaving(true)
+    try {
+      const response = await fetch(`/api/workspaces/${workspaceId}/weight`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ weightKg, notes: notes.trim() || null }),
+      })
+      if (!response.ok) throw new Error('Failed to log weight')
+      showToast('Weight logged', 'success')
+      setWeight('')
+      setNotes('')
+      onLogged?.()
+    } catch {
+      showToast('Failed to log weight', 'error')
+    } finally {
+      setSaving(false)
+    }
+  }
+
+  return (
+    <div className="space-y-4">
+      {/* Weight Input */}
+      <div>
+        <label className="block text-sm font-medium text-secondary-700 mb-2">Weight</label>
+        <div className="relative">
+          <input
+            type="text"
+            inputMode="decimal"
+            value={weight}
+            onChange={(e) => setWeight(e.target.value)}
+            placeholder={unit === 'kg' ? '70.0' : '154.0'}
+            className="w-full px-4 py-4 text-3xl font-bold text-center border border-border rounded-card focus:outline-none focus:ring-2 focus:ring-primary-200 focus:border-primary-500"
+          />
+          <div className="absolute right-3 top-1/2 -translate-y-1/2 flex rounded-lg border border-border overflow-hidden">
+            <button
+              type="button"
+              onClick={() => setUnit('kg')}
+              className={`px-3 py-1 text-sm font-medium ${unit === 'kg' ? 'bg-primary-500 text-white' : 'text-secondary-500'}`}
+            >
+              kg
+            </button>
+            <button
+              type="button"
+              onClick={() => setUnit('lbs')}
+              className={`px-3 py-1 text-sm font-medium ${unit === 'lbs' ? 'bg-primary-500 text-white' : 'text-secondary-500'}`}
+            >
+              lbs
+            </button>
+          </div>
+        </div>
+      </div>
+
+      {/* Notes */}
+      <div>
+        <label className="block text-sm font-medium text-secondary-700 mb-2">Notes (optional)</label>
+        <textarea
+          value={notes}
+          onChange={(e) => setNotes(e.target.value)}
+          placeholder="Morning weight, before meals..."
+          rows={2}
+          className="w-full px-3 py-2 border border-border rounded-lg text-base focus:outline-none focus:ring-2 focus:ring-primary-200 focus:border-primary-500 resize-none"
+        />
+      </div>
+
+      <Button onClick={handleSubmit} fullWidth loading={saving}>
+        <Scale className="w-5 h-5 mr-2" />
+        Log Weight
+      </Button>
+    </div>
+  )
+}