feat(flow): map SKU + auto-retry consolidated banner

After saving a SKU mapping, check for SKIPPED orders containing that
SKU and show a floating banner with count + "Importa" button. Batch
retries up to 20 orders and shows result feedback.

Backend:
- get_skipped_orders_with_sku() in sqlite_service.py
- GET /api/orders/by-sku/{sku}/pending endpoint
- POST /api/orders/batch-retry endpoint (max 20, sequential)

Frontend:
- Auto-retry banner after quickMap save with batch import button
- Success/error feedback, auto-dismiss after 15s

Cache-bust: shared.js?v=19

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

api/app/services/sqlite_service.py

@@ -960,6 +960,24 @@ async def set_app_setting(key: str, value: str):
         await db.close()
 
 
+# ── SKU-based order lookup ────────────────────────
+
+async def get_skipped_orders_with_sku(sku: str) -> list[str]:
+    """Get order_numbers of SKIPPED orders that contain the given SKU."""
+    db = await get_sqlite()
+    try:
+        cursor = await db.execute("""
+            SELECT DISTINCT oi.order_number
+            FROM order_items oi
+            JOIN orders o ON o.order_number = oi.order_number
+            WHERE oi.sku = ? AND o.status = 'SKIPPED'
+        """, (sku,))
+        rows = await cursor.fetchall()
+        return [row[0] for row in rows]
+    finally:
+        await db.close()
+
+
 # ── Price Sync Runs ───────────────────────────────
 
 async def get_price_sync_runs(page: int = 1, per_page: int = 20):