[split-required] Split 500-850 LOC files (batch 2)

backend-lehrer (10 files):
- game/database.py (785 → 5), correction_api.py (683 → 4)
- classroom_engine/antizipation.py (676 → 5)
- llm_gateway schools/edu_search already done in prior batch

klausur-service (12 files):
- orientation_crop_api.py (694 → 5), pdf_export.py (677 → 4)
- zeugnis_crawler.py (676 → 5), grid_editor_api.py (671 → 5)
- eh_templates.py (658 → 5), mail/api.py (651 → 5)
- qdrant_service.py (638 → 5), training_api.py (625 → 4)

website (6 pages):
- middleware (696 → 8), mail (733 → 6), consent (628 → 8)
- compliance/risks (622 → 5), export (502 → 5), brandbook (629 → 7)

studio-v2 (3 components):
- B2BMigrationWizard (848 → 3), CleanupPanel (765 → 2)
- dashboard-experimental (739 → 2)

admin-lehrer (4 files):
- uebersetzungen (769 → 4), manager (670 → 2)
- ChunkBrowserQA (675 → 6), dsfa/page (674 → 5)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

admin-lehrer/app/(admin)/ai/rag/components/ChunkBrowserSidebar.tsx

@@ -0,0 +1,81 @@
+'use client'
+
+import React from 'react'
+import { RegGroupKey, GROUP_LABELS, GROUP_ORDER } from './ChunkBrowserConstants'
+
+interface ChunkBrowserSidebarProps {
+  filterSearch: string
+  setFilterSearch: (v: string) => void
+  countsLoading: boolean
+  filteredRegulations: Record<RegGroupKey, { code: string; name: string; type: string }[]>
+  regulationCounts: Record<string, number>
+  selectedRegulation: string | null
+  collapsedGroups: Set<string>
+  onSelectRegulation: (code: string) => void
+  onToggleGroup: (group: string) => void
+}
+
+export function ChunkBrowserSidebar({
+  filterSearch,
+  setFilterSearch,
+  countsLoading,
+  filteredRegulations,
+  regulationCounts,
+  selectedRegulation,
+  collapsedGroups,
+  onSelectRegulation,
+  onToggleGroup,
+}: ChunkBrowserSidebarProps) {
+  return (
+    <div className="w-56 flex-shrink-0 bg-white rounded-xl border border-slate-200 flex flex-col min-h-0">
+      <div className="flex-shrink-0 p-3 border-b border-slate-100">
+        <input
+          type="text"
+          value={filterSearch}
+          onChange={(e) => setFilterSearch(e.target.value)}
+          placeholder="Suche..."
+          className="w-full px-2 py-1.5 border rounded-lg text-sm focus:ring-2 focus:ring-teal-500"
+        />
+        {countsLoading && (
+          <div className="text-xs text-slate-400 mt-1 animate-pulse">Counts laden...</div>
+        )}
+      </div>
+      <div className="flex-1 overflow-y-auto min-h-0">
+        {GROUP_ORDER.map(group => {
+          const items = filteredRegulations[group]
+          if (items.length === 0) return null
+          const isCollapsed = collapsedGroups.has(group)
+          return (
+            <div key={group}>
+              <button
+                onClick={() => onToggleGroup(group)}
+                className="w-full px-3 py-1.5 text-left text-xs font-semibold text-slate-500 bg-slate-50 hover:bg-slate-100 flex items-center justify-between sticky top-0 z-10"
+              >
+                <span>{GROUP_LABELS[group]}</span>
+                <span className="text-slate-400">{isCollapsed ? '+' : '-'}</span>
+              </button>
+              {!isCollapsed && items.map(reg => {
+                const count = regulationCounts[reg.code] ?? 0
+                const isSelected = selectedRegulation === reg.code
+                return (
+                  <button
+                    key={reg.code}
+                    onClick={() => onSelectRegulation(reg.code)}
+                    className={`w-full px-3 py-1.5 text-left text-sm flex items-center justify-between hover:bg-teal-50 transition-colors ${
+                      isSelected ? 'bg-teal-100 text-teal-900 font-medium' : 'text-slate-700'
+                    }`}
+                  >
+                    <span className="truncate text-xs">{reg.name || reg.code}</span>
+                    <span className={`text-xs tabular-nums flex-shrink-0 ml-1 ${count > 0 ? 'text-slate-500' : 'text-slate-300'}`}>
+                      {count > 0 ? count.toLocaleString() : '\u2014'}
+                    </span>
+                  </button>
+                )
+              })}
+            </div>
+          )
+        })}
+      </div>
+    </div>
+  )
+}