feat: add SubscriptionPage - user-facing subscription info

User can now view:
- Current tier (Free, Basic, Premium, Selfhosted) with icon
- Trial status and end date
- Access expiration date
- Feature limits with usage bars
- Progress indicators (green/orange/red based on usage)
- Reset period info (daily/monthly/never)

Coupon redemption:
- Input field for coupon code
- Auto-uppercase, monospace display
- Enter key support
- Success/error feedback
- Auto-refresh after redemption

Features:
- Clean card-based layout
- Visual tier badges with colors
- Progress bars for count limits
- Trial and access warnings
- Integrated in Settings page

Link added to SettingsPage:
- "👑 Abo-Status, Limits & Coupon einlösen"
- Easy access for all users

Phase 3 complete - all user-facing subscription features done!

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

frontend/src/App.jsx

@@ -25,6 +25,7 @@ import AdminFeaturesPage from './pages/AdminFeaturesPage'
 import AdminTiersPage from './pages/AdminTiersPage'
 import AdminCouponsPage from './pages/AdminCouponsPage'
 import AdminUserRestrictionsPage from './pages/AdminUserRestrictionsPage'
+import SubscriptionPage from './pages/SubscriptionPage'
 import './app.css'
 
 function Nav() {
@@ -125,6 +126,7 @@ function AppShell() {
           <Route path="/admin/tiers" element={<AdminTiersPage/>}/>
           <Route path="/admin/coupons" element={<AdminCouponsPage/>}/>
           <Route path="/admin/user-restrictions" element={<AdminUserRestrictionsPage/>}/>
+          <Route path="/subscription" element={<SubscriptionPage/>}/>
         </Routes>
       </main>
       <Nav/>

frontend/src/pages/SettingsPage.jsx

@@ -234,6 +234,16 @@ export default function SettingsPage() {
     <div>
       <h1 className="page-title">Einstellungen</h1>
 
+      {/* Subscription */}
+      <div className="card section-gap">
+        <div className="card-title">Mein Abo</div>
+        <Link to="/subscription" style={{textDecoration:'none'}}>
+          <button className="btn btn-secondary btn-full">
+            👑 Abo-Status, Limits & Coupon einlösen
+          </button>
+        </Link>
+      </div>
+
       {/* Profile list */}
       <div className="card section-gap">
         <div className="card-title">Profile ({profiles.length})</div>

frontend/src/pages/SubscriptionPage.jsx

@@ -0,0 +1,241 @@
+import { useState, useEffect } from 'react'
+import { Gift, AlertCircle, TrendingUp, Award } from 'lucide-react'
+import { api } from '../utils/api'
+
+export default function SubscriptionPage() {
+  const [loading, setLoading] = useState(true)
+  const [error, setError] = useState('')
+  const [subscription, setSubscription] = useState(null)
+  const [usage, setUsage] = useState([])
+  const [limits, setLimits] = useState([])
+  const [couponCode, setCouponCode] = useState('')
+  const [redeeming, setRedeeming] = useState(false)
+  const [couponSuccess, setCouponSuccess] = useState('')
+
+  useEffect(() => {
+    loadData()
+  }, [])
+
+  async function loadData() {
+    try {
+      setLoading(true)
+      const [subData, usageData, limitsData] = await Promise.all([
+        api.getMySubscription(),
+        api.getMyUsage(),
+        api.getMyLimits()
+      ])
+      setSubscription(subData)
+      setUsage(usageData)
+      setLimits(limitsData)
+      setError('')
+    } catch (e) {
+      setError(e.message)
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  async function handleRedeemCoupon() {
+    if (!couponCode.trim()) return
+
+    try {
+      setRedeeming(true)
+      setError('')
+      setCouponSuccess('')
+      await api.redeemCoupon(couponCode.trim().toUpperCase())
+      setCouponSuccess('Coupon erfolgreich eingelöst!')
+      setCouponCode('')
+      await loadData()
+    } catch (e) {
+      setError(e.message)
+    } finally {
+      setRedeeming(false)
+    }
+  }
+
+  if (loading) return (
+    <div style={{ display: 'flex', justifyContent: 'center', padding: 40 }}>
+      <div className="spinner" />
+    </div>
+  )
+
+  const tierColors = {
+    free: { bg: 'var(--surface2)', color: 'var(--text2)', icon: '🆓' },
+    basic: { bg: '#E3F2FD', color: '#1565C0', icon: '⭐' },
+    premium: { bg: '#F3E5F5', color: '#6A1B9A', icon: '👑' },
+    selfhosted: { bg: 'var(--accent-light)', color: 'var(--accent-dark)', icon: '🏠' }
+  }
+
+  const currentTier = subscription?.current_tier || 'free'
+  const tierStyle = tierColors[currentTier] || tierColors.free
+
+  return (
+    <div style={{ paddingBottom: 40 }}>
+      {/* Header */}
+      <div style={{ marginBottom: 20 }}>
+        <div style={{ fontSize: 20, fontWeight: 700, color: 'var(--text1)' }}>
+          Mein Abo
+        </div>
+        <div style={{ fontSize: 13, color: 'var(--text3)', marginTop: 4 }}>
+          Tier, Limits und Nutzung
+        </div>
+      </div>
+
+      {/* Messages */}
+      {error && (
+        <div style={{
+          padding: 12, background: 'var(--danger)', color: 'white',
+          borderRadius: 8, marginBottom: 16, fontSize: 14
+        }}>
+          {error}
+        </div>
+      )}
+      {couponSuccess && (
+        <div style={{
+          padding: 12, background: 'var(--accent)', color: 'white',
+          borderRadius: 8, marginBottom: 16, fontSize: 14
+        }}>
+          {couponSuccess}
+        </div>
+      )}
+
+      {/* Current Tier Card */}
+      <div className="card" style={{ padding: 20, marginBottom: 16 }}>
+        <div style={{ display: 'flex', alignItems: 'center', gap: 12, marginBottom: 16 }}>
+          <div style={{
+            width: 48, height: 48, borderRadius: 12,
+            background: tierStyle.bg,
+            display: 'flex', alignItems: 'center', justifyContent: 'center',
+            fontSize: 24
+          }}>
+            {tierStyle.icon}
+          </div>
+          <div style={{ flex: 1 }}>
+            <div style={{ fontSize: 12, color: 'var(--text3)', textTransform: 'uppercase', fontWeight: 600 }}>
+              Aktueller Tier
+            </div>
+            <div style={{ fontSize: 20, fontWeight: 700, color: tierStyle.color }}>
+              {currentTier.charAt(0).toUpperCase() + currentTier.slice(1)}
+            </div>
+          </div>
+        </div>
+
+        {subscription?.trial_ends_at && new Date(subscription.trial_ends_at) > new Date() && (
+          <div style={{
+            padding: 10, background: '#FFF3CD', borderRadius: 8,
+            fontSize: 13, color: '#856404', display: 'flex', gap: 8, alignItems: 'center'
+          }}>
+            <AlertCircle size={16} />
+            <div>
+              <strong>Trial aktiv:</strong> Endet am {new Date(subscription.trial_ends_at).toLocaleDateString('de-DE')}
+            </div>
+          </div>
+        )}
+
+        {subscription?.access_until && (
+          <div style={{
+            padding: 10, background: 'var(--accent-light)', borderRadius: 8,
+            fontSize: 13, color: 'var(--accent-dark)', display: 'flex', gap: 8, alignItems: 'center',
+            marginTop: 12
+          }}>
+            <Award size={16} />
+            <div>
+              <strong>Zugriff bis:</strong> {new Date(subscription.access_until).toLocaleDateString('de-DE')}
+            </div>
+          </div>
+        )}
+      </div>
+
+      {/* Feature Limits */}
+      <div className="card" style={{ padding: 20, marginBottom: 16 }}>
+        <div style={{
+          fontSize: 14, fontWeight: 600, marginBottom: 12,
+          display: 'flex', alignItems: 'center', gap: 6
+        }}>
+          <TrendingUp size={16} color="var(--accent)" />
+          Feature-Limits & Nutzung
+        </div>
+
+        {limits.length === 0 ? (
+          <div style={{ textAlign: 'center', padding: 20, color: 'var(--text3)', fontSize: 13 }}>
+            Keine Limits konfiguriert
+          </div>
+        ) : (
+          <div style={{ display: 'grid', gap: 12 }}>
+            {limits.map(limit => {
+              const usageEntry = usage.find(u => u.feature_id === limit.feature_id)
+              const used = usageEntry?.usage_count || 0
+              const limitValue = limit.limit_value
+              const percentage = limitValue ? Math.min((used / limitValue) * 100, 100) : 0
+
+              return (
+                <div key={limit.feature_id} style={{
+                  padding: 12, background: 'var(--surface)', borderRadius: 8
+                }}>
+                  <div style={{ display: 'flex', justifyContent: 'space-between', marginBottom: 8 }}>
+                    <div style={{ fontWeight: 500, fontSize: 13 }}>{limit.feature_name}</div>
+                    <div style={{ fontSize: 13, color: 'var(--text3)' }}>
+                      {used} / {limitValue === null ? '∞' : limitValue}
+                    </div>
+                  </div>
+
+                  {limitValue !== null && (
+                    <div style={{
+                      height: 6, background: 'var(--border)', borderRadius: 3, overflow: 'hidden'
+                    }}>
+                      <div style={{
+                        width: `${percentage}%`,
+                        height: '100%',
+                        background: percentage > 90 ? 'var(--danger)' : percentage > 70 ? '#FFA726' : 'var(--accent)',
+                        transition: 'width 0.3s'
+                      }} />
+                    </div>
+                  )}
+
+                  {limit.reset_period !== 'never' && (
+                    <div style={{ fontSize: 11, color: 'var(--text3)', marginTop: 4 }}>
+                      Reset: {limit.reset_period === 'daily' ? 'Täglich' : 'Monatlich'}
+                    </div>
+                  )}
+                </div>
+              )
+            })}
+          </div>
+        )}
+      </div>
+
+      {/* Coupon Redemption */}
+      <div className="card" style={{ padding: 20 }}>
+        <div style={{
+          fontSize: 14, fontWeight: 600, marginBottom: 12,
+          display: 'flex', alignItems: 'center', gap: 6
+        }}>
+          <Gift size={16} color="var(--accent)" />
+          Coupon einlösen
+        </div>
+
+        <div style={{ fontSize: 12, color: 'var(--text3)', marginBottom: 12 }}>
+          Hast du einen Coupon-Code? Löse ihn hier ein um Zugriff auf Premium-Features zu erhalten.
+        </div>
+
+        <div style={{ display: 'flex', gap: 8 }}>
+          <input
+            className="form-input"
+            style={{ flex: 1, textTransform: 'uppercase', fontFamily: 'monospace' }}
+            value={couponCode}
+            onChange={(e) => setCouponCode(e.target.value)}
+            placeholder="Z.B. PROMO-2026"
+            onKeyPress={(e) => e.key === 'Enter' && handleRedeemCoupon()}
+          />
+          <button
+            className="btn btn-primary"
+            onClick={handleRedeemCoupon}
+            disabled={!couponCode.trim() || redeeming}
+          >
+            {redeeming ? 'Prüfen...' : 'Einlösen'}
+          </button>
+        </div>
+      </div>
+    </div>
+  )
+}