fix(sap_s4hana): preserve $ in OData query params; reject empty items array

- buildOdataUrl now constructs query strings manually with
  encodeURIComponent and restores literal "$" so OData system options
  ($filter, $top, $select, $expand, $orderby, $skip, $format) reach
  SAP and any intermediary proxies/WAFs as-is, not as "%24filter".
  URLSearchParams was percent-encoding "$" to "%24" which most ICMs
  decode but some intermediaries silently drop, returning unfiltered
  results.
- create_sales_order now rejects an empty items array (matches
  create_purchase_requisition) so callers get a clear client-side
  error instead of an opaque SAP validation failure on the deep-insert.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: waleedlatif1

apps/sim/app/api/tools/sap_s4hana/proxy/route.ts

@@ -420,12 +420,13 @@ function buildOdataUrl(req: ProxyRequest, pathOverride?: string): string {
   if (!req.query || Object.keys(req.query).length === 0) {
     return base
   }
-  const search = new URLSearchParams()
+  const encode = (s: string) => encodeURIComponent(s).replace(/%24/g, '$')
+  const parts: string[] = []
   for (const [key, value] of Object.entries(req.query)) {
     if (value === undefined || value === null) continue
-    search.append(key, String(value))
+    parts.push(`${encode(key)}=${encode(String(value))}`)
   }
-  const queryString = search.toString()
+  const queryString = parts.join('&')
   if (!queryString) return base
   return base.includes('?') ? `${base}&${queryString}` : `${base}?${queryString}`
 }

apps/sim/tools/sap_s4hana/create_sales_order.ts

@@ -125,8 +125,8 @@ export const createSalesOrderTool: ToolConfig<CreateSalesOrderParams, SapProxyRe
     headers: () => ({ 'Content-Type': 'application/json' }),
     body: (params) => {
       const items = parseJsonInput<Array<Record<string, unknown>>>(params.items, 'items')
-      if (!Array.isArray(items)) {
-        throw new Error('items must be a JSON array of sales order item objects')
+      if (!Array.isArray(items) || items.length === 0) {
+        throw new Error('items must be a non-empty JSON array of sales order item objects')
       }
       const extra = parseJsonInput<Record<string, unknown>>(params.body, 'body') ?? {}
       const payload: Record<string, unknown> = {