feat(iace): DSMS-CID-Badge im Tech-File-Export + aggregierter Bulk-Diff

Punkt 1 — UI-CID-Badge nach erfolgreichem Tech-File-Export:
- archiveTechFile setzt X-DSMS-CID / X-DSMS-Filename / X-DSMS-Size response
  headers + Access-Control-Expose-Headers, sobald DSMS-Archive durchlief
- Split iace_handler_techfile.go (war ueber 500 LOC) → archiveTechFile lebt
  jetzt in iace_handler_techfile_archive.go, setDSMSResponseHeaders als
  pure Helper mit 3 unit tests
- Next.js IACE-Proxy forwarded die X-DSMS-* Header und erkennt jetzt auch
  XLSX/DOCX/MD als Binary-Response (vorher nur PDF/ZIP/octet-stream)
- ExportCIDBadge.tsx zeigt CID, Filename, Groesse + Kopieren-Button +
  "Verlauf anzeigen" (oeffnet CIDHistoryModal)

Punkt 2 — Bulk-Diff Report V1 → V_latest:
- Neuer Endpoint GET /api/v1/documents/{cid}/bulk-diff im dsms-gateway:
  laeuft parent_cid-Kette ab, berechnet chronologische Step-Diffs,
  aggregiert Totals (added/removed lines, metadata_fields_changed,
  binary_steps). Edge-Cases: einzelne Version, binaere Steps, abgebrochene
  Kette
- BulkDiffPanel.tsx zeigt 4-Stat-Header + Step-Tabelle
- CIDHistoryModal bekommt Toggle-Button "Bulk-Diff V1 → V_latest anzeigen"
  neben dem Versions-Counter; damit auch vom IACE-Export-Badge erreichbar

Tests: 3 neue Go-Tests, 4 neue pytest-Tests, alle gruen

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

admin-compliance/app/sdk/iace/[projectId]/tech-file/_components/ExportCIDBadge.tsx

@@ -0,0 +1,95 @@
+'use client'
+
+import { useState } from 'react'
+import CIDHistoryModal from '@/app/sdk/audit-timeline/_components/CIDHistoryModal'
+
+export interface LastExport {
+  cid: string
+  filename: string
+  size: number
+  format: string
+}
+
+interface Props {
+  lastExport: LastExport | null
+  onDismiss: () => void
+}
+
+function formatBytes(n: number): string {
+  if (n < 1024) return `${n} B`
+  if (n < 1024 * 1024) return `${(n / 1024).toFixed(1)} KB`
+  return `${(n / 1024 / 1024).toFixed(2)} MB`
+}
+
+export function ExportCIDBadge({ lastExport, onDismiss }: Props) {
+  const [showHistory, setShowHistory] = useState(false)
+  const [copied, setCopied] = useState(false)
+
+  if (!lastExport) return null
+
+  async function copyToClipboard() {
+    if (!lastExport) return
+    try {
+      await navigator.clipboard.writeText(lastExport.cid)
+      setCopied(true)
+      setTimeout(() => setCopied(false), 1500)
+    } catch {
+      // clipboard not available — silent
+    }
+  }
+
+  return (
+    <>
+      <div className="rounded-xl border border-emerald-200 bg-emerald-50 dark:border-emerald-800 dark:bg-emerald-900/20 p-4">
+        <div className="flex items-start gap-3">
+          <div className="rounded-full bg-emerald-500 p-1 flex-shrink-0 mt-0.5">
+            <svg className="w-4 h-4 text-white" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={3} d="M5 13l4 4L19 7" />
+            </svg>
+          </div>
+          <div className="flex-1 min-w-0">
+            <div className="text-sm font-semibold text-emerald-900 dark:text-emerald-200">
+              CE-Akte exportiert und in DSMS archiviert
+            </div>
+            <div className="mt-1 text-xs text-emerald-800 dark:text-emerald-300">
+              {lastExport.filename} · {formatBytes(lastExport.size)} · Format {lastExport.format.toUpperCase()}
+            </div>
+            <div className="mt-2 flex items-center gap-2 flex-wrap">
+              <span className="text-[10px] uppercase tracking-wide text-emerald-700 dark:text-emerald-400 font-semibold">
+                CID
+              </span>
+              <code className="font-mono text-xs text-emerald-900 dark:text-emerald-100 bg-white/60 dark:bg-black/20 px-2 py-0.5 rounded select-all break-all">
+                {lastExport.cid}
+              </code>
+              <button
+                onClick={copyToClipboard}
+                className="text-[11px] text-emerald-700 hover:text-emerald-900 dark:text-emerald-400 dark:hover:text-emerald-200 underline"
+                title="CID in Zwischenablage kopieren"
+              >
+                {copied ? '✓ Kopiert' : 'Kopieren'}
+              </button>
+              <button
+                onClick={() => setShowHistory(true)}
+                className="text-[11px] text-emerald-700 hover:text-emerald-900 dark:text-emerald-400 dark:hover:text-emerald-200 underline"
+                title="DSMS-Versionsverlauf und Diffs anzeigen"
+              >
+                Verlauf anzeigen
+              </button>
+            </div>
+          </div>
+          <button
+            onClick={onDismiss}
+            className="text-emerald-600 hover:text-emerald-800 dark:text-emerald-400 dark:hover:text-emerald-200 p-1 flex-shrink-0"
+            title="Hinweis schliessen"
+            aria-label="Hinweis schliessen"
+          >
+            <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
+            </svg>
+          </button>
+        </div>
+      </div>
+      {showHistory && <CIDHistoryModal cid={lastExport.cid} onClose={() => setShowHistory(false)} />}
+    </>
+  )
+}