feat(ancpi): complete ePay UI + dedup protection

UI Components (Phase 4):
- epay-connect.tsx: connection widget with credit badge, auto-connect
- epay-order-button.tsx: per-parcel "Extras CF" button with status
- epay-tab.tsx: full "Extrase CF" tab with orders table, filters,
  download/refresh actions, new order form
- Minimal changes to parcel-sync-module.tsx: 5th tab + button on
  search results + ePay connect widget

Dedup Protection:
- epay-queue.ts: batch-level dedup (60s window, canonical key from
  sorted cadastral numbers)
- order/route.ts: request nonce idempotency (60s cache)
- test/route.ts: refresh protection (30s cache)

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

src/modules/parcel-sync/services/epay-queue.ts

@@ -40,8 +40,37 @@ type BatchJob = {
 const g = globalThis as {
   __epayBatchQueue?: BatchJob[];
   __epayQueueProcessing?: boolean;
+  __epayDedupMap?: Map<string, { timestamp: number; extractIds: string[] }>;
 };
 if (!g.__epayBatchQueue) g.__epayBatchQueue = [];
+if (!g.__epayDedupMap) g.__epayDedupMap = new Map();
+
+/** TTL for dedup entries in milliseconds (60 seconds). */
+const DEDUP_TTL_MS = 60_000;
+
+/**
+ * Build a dedup key from a list of cadastral numbers.
+ * Sorted and joined so order doesn't matter.
+ */
+function batchDedupKey(inputs: CfExtractCreateInput[]): string {
+  return inputs
+    .map((i) => i.nrCadastral)
+    .sort()
+    .join(",");
+}
+
+/**
+ * Remove expired entries from the dedup map.
+ */
+function cleanupDedupMap(): void {
+  const now = Date.now();
+  const map = g.__epayDedupMap!;
+  for (const [key, entry] of map) {
+    if (now - entry.timestamp > DEDUP_TTL_MS) {
+      map.delete(key);
+    }
+  }
+}
 
 /* ------------------------------------------------------------------ */
 /*  Public API                                                         */
@@ -64,12 +93,27 @@ export async function enqueueOrder(
  * Enqueue a batch of CF extract orders.
  * Creates all DB records, then processes as ONE ePay order.
  * Returns the CfExtract IDs immediately.
+ *
+ * Dedup protection: if the same set of cadastral numbers was enqueued
+ * within the last 60 seconds, returns the existing extract IDs instead
+ * of creating duplicate DB records and orders.
  */
 export async function enqueueBatch(
   inputs: CfExtractCreateInput[],
 ): Promise<string[]> {
   if (inputs.length === 0) return [];
 
+  // ── Dedup check ──
+  cleanupDedupMap();
+  const dedupKey = batchDedupKey(inputs);
+  const existing = g.__epayDedupMap!.get(dedupKey);
+  if (existing && Date.now() - existing.timestamp < DEDUP_TTL_MS) {
+    console.log(
+      `[epay-queue] Dedup hit: batch [${dedupKey}] was enqueued ${Math.round((Date.now() - existing.timestamp) / 1000)}s ago — returning existing IDs`,
+    );
+    return existing.extractIds;
+  }
+
   const items: QueueItem[] = [];
 
   for (const input of inputs) {
@@ -99,6 +143,14 @@ export async function enqueueBatch(
     items.push({ extractId: record.id, input });
   }
 
+  const extractIds = items.map((i) => i.extractId);
+
+  // ── Record in dedup map ──
+  g.__epayDedupMap!.set(dedupKey, {
+    timestamp: Date.now(),
+    extractIds,
+  });
+
   g.__epayBatchQueue!.push({ items });
 
   console.log(
@@ -108,7 +160,7 @@ export async function enqueueBatch(
   // Start processing if not already running
   void processQueue();
 
-  return items.map((i) => i.extractId);
+  return extractIds;
 }
 
 /**