fix(gateway): stop Qdrant upsert aborts (semantic cache was being skipped)

Qdrant upserts were failing with 'This operation was aborted' ~32x/2h,
so semantic moderation cache entries were silently dropped. Root cause:
upsertQdrantPoint ran ensureQdrantCollection() on EVERY call — a GET
(and sometimes DELETE+PUT) round-trip — while the request AbortController
had only a 10s timeout. Under moderation load Qdrant is busy (the
gmw_text_moderation collection is not yet HNSW-indexed, so searches are
full-scans), the extra round-trips pushed the upsert past 10s, and the
client aborted it.

- Memoise ensureQdrantCollection() at module scope so the collection is
  verified exactly once per process (resetQdrantCollectionCache() for
  tests / config reload).
- Bump the upsert request timeout 10s -> 30s so a transiently busy
  Qdrant no longer aborts the write.

Qdrant server itself is healthy (<100ms for direct upsert; collection is
green), so no server-side change is needed. Semantic cache should now
populate reliably.

services/discord-gateway/src/modules/ai-moderation/qdrantClient.ts

@@ -17,6 +17,18 @@ import { config } from "../../shared/config/config.js";
 
 const log = createChildLogger("qdrant");
 
+// ensureQdrantCollection performs a network round-trip (GET, possibly
+// DELETE+PUT). Running it on every upsert adds 1-3 HTTP calls per
+// moderation verdict, which under Qdrant load pushes the upsert past the
+// request timeout and aborts it ("This operation was aborted"). Memoise the
+// result so the collection is only verified once per process lifetime.
+let ensureCollectionPromise: Promise<boolean> | null = null;
+
+/** Reset the memoised ensure result (used by tests / config reload). */
+export function resetQdrantCollectionCache(): void {
+  ensureCollectionPromise = null;
+}
+
 export interface QdrantVerdictPayload {
   text: string;
   flags: string; // JSON string of the full moderation result
@@ -97,13 +109,18 @@ export function qdrantPointId(cacheKey: string): number {
 export async function ensureQdrantCollection(
   vectorSize: number,
 ): Promise<boolean> {
+  if (ensureCollectionPromise) return ensureCollectionPromise;
+  ensureCollectionPromise = (async () => {
     try {
       // 404 = collection doesn't exist yet → create it.
       let existing: {
         result?: { config?: { params?: { vectors?: { size?: number } } } };
       } | null = null;
       try {
-      existing = (await request("GET", `/collections/${collectionName()}`)) as {
+        existing = (await request(
+          "GET",
+          `/collections/${collectionName()}`,
+        )) as {
           result?: { config?: { params?: { vectors?: { size?: number } } } };
         };
       } catch (error) {
@@ -137,6 +154,8 @@ export async function ensureQdrantCollection(
       );
       return false;
     }
+  })();
+  return ensureCollectionPromise;
 }
 
 /** Upsert one embedding + verdict payload point. Returns false on failure. */
@@ -147,10 +166,15 @@ export async function upsertQdrantPoint(
 ): Promise<boolean> {
   try {
     if (!(await ensureQdrantCollection(vector.length))) return false;
-    await request("PUT", `/collections/${collectionName()}/points`, {
+    await request(
+      "PUT",
+      `/collections/${collectionName()}/points`,
+      {
         points: [{ id: qdrantPointId(cacheKey), vector, payload }],
         wait: true,
-    });
+      },
+      30_000,
+    );
     return true;
   } catch (error) {
     log.warn(