feat(v9d): integrate training type UI components

Phase 1b - UI Integration:
===========================

ActivityPage:
- Replace old activity type dropdown with TrainingTypeSelect
- Add training_type_id, training_category, training_subcategory to form
- Two-level selection (category → subcategory)

Dashboard:
- Add TrainingTypeDistribution card (pie chart)
- Shows last 28 days activity distribution by type
- Conditional rendering (only if activities exist)

Still TODO:
- History: Add type badge display (next commit)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/pages/ActivityPage.jsx

@@ -3,6 +3,7 @@ import { Upload, Pencil, Trash2, Check, X, CheckCircle } from 'lucide-react'
 import { BarChart, Bar, XAxis, YAxis, Tooltip, ResponsiveContainer, CartesianGrid } from 'recharts'
 import { api } from '../utils/api'
 import UsageBadge from '../components/UsageBadge'
+import TrainingTypeSelect from '../components/TrainingTypeSelect'
 import dayjs from 'dayjs'
 import 'dayjs/locale/de'
 dayjs.locale('de')
@@ -18,7 +19,10 @@ function empty() {
     date: dayjs().format('YYYY-MM-DD'),
     activity_type: 'Traditionelles Krafttraining',
     duration_min: '', kcal_active: '',
-    hr_avg: '', hr_max: '', rpe: '', notes: ''
+    hr_avg: '', hr_max: '', rpe: '', notes: '',
+    training_type_id: null,
+    training_category: null,
+    training_subcategory: null
   }
 }
 
@@ -89,11 +93,19 @@ function EntryForm({ form, setForm, onSave, onCancel, saveLabel='Speichern', sav
         <input type="date" className="form-input" style={{width:140}} value={form.date} onChange={e=>set('date',e.target.value)}/>
         <span className="form-unit"/>
       </div>
-      <div className="form-row">
-        <label className="form-label">Trainingsart</label>
-        <select className="form-select" value={form.activity_type} onChange={e=>set('activity_type',e.target.value)}>
-          {ACTIVITY_TYPES.map(t=><option key={t} value={t}>{t}</option>)}
-        </select>
+      <div style={{marginBottom:12}}>
+        <TrainingTypeSelect
+          value={form.training_type_id}
+          onChange={(typeId, category, subcategory) => {
+            setForm(f => ({
+              ...f,
+              training_type_id: typeId,
+              training_category: category,
+              training_subcategory: subcategory
+            }))
+          }}
+          required={false}
+        />
       </div>
       <div className="form-row">
         <label className="form-label">Dauer</label>

frontend/src/pages/Dashboard.jsx

@@ -10,6 +10,7 @@ import { useProfile } from '../context/ProfileContext'
 import { getBfCategory } from '../utils/calc'
 import TrialBanner from '../components/TrialBanner'
 import EmailVerificationBanner from '../components/EmailVerificationBanner'
+import TrainingTypeDistribution from '../components/TrainingTypeDistribution'
 import { getInterpretation, getStatusColor, getStatusBg } from '../utils/interpret'
 import Markdown from '../utils/Markdown'
 import dayjs from 'dayjs'
@@ -470,6 +471,20 @@ export default function Dashboard() {
           )}
         </div>
 
+        {/* Training Type Distribution */}
+        {activities.length > 0 && (
+          <div className="card section-gap" style={{marginBottom:16}}>
+            <div style={{display:'flex',justifyContent:'space-between',alignItems:'center',marginBottom:12}}>
+              <div style={{fontWeight:600,fontSize:13}}>🏋️ Trainingstyp-Verteilung</div>
+              <button style={{background:'none',border:'none',fontSize:12,color:'var(--accent)',cursor:'pointer'}}
+                onClick={()=>nav('/activity')}>
+                Details →
+              </button>
+            </div>
+            <TrainingTypeDistribution days={28} />
+          </div>
+        )}
+
         {/* Latest AI insight */}
         <div className="card section-gap">
           <div style={{display:'flex',alignItems:'center',justifyContent:'space-between',marginBottom:8}}>