refactor: remove cold-path cache key preflight

app/javascript/dashboard/api/CacheEnabledApiClient.js

@@ -25,13 +25,6 @@ class CacheEnabledApiClient extends ApiClient {
     return axios.get(this.url);
   }
 
-  async getCacheKeyFromServer() {
-    const response = await axios.get(
-      `/api/v1/accounts/${this.accountIdFromRoute}/cache_keys`
-    );
-    return response.data.cache_keys?.[this.cacheModelName] ?? null;
-  }
-
   // eslint-disable-next-line class-methods-use-this
   extractDataFromResponse(response) {
     return response.data.payload;
@@ -63,16 +56,10 @@ class CacheEnabledApiClient extends ApiClient {
       return this.marshallData(localData);
     }
 
-    // Empty IDB (first load or wiped): capture the authoritative key before
-    // persisting rows so future boots can revalidate this cached data.
-    let serverKey = null;
-    try {
-      serverKey = await this.getCacheKeyFromServer();
-    } catch {
-      // Ignore error. The network fetch below should still work, and storing
-      // null keeps this cache eligible for boot-time revalidation later.
-    }
-    return this.refetchAndCommit(serverKey);
+    // Empty IDB (first load or wiped): fetch data without a cache key. The
+    // next pushed key map won't match the missing key and will refetch once,
+    // stamping the authoritative key — the client never pulls keys itself.
+    return this.refetchAndCommit(null);
   }
 
   async refetchAndCommit(newKey = null) {
@@ -89,7 +76,7 @@ class CacheEnabledApiClient extends ApiClient {
       });
 
       await this.dataManager.setCacheKeys({
-        [this.cacheModelName]: newKey === undefined ? null : newKey,
+        [this.cacheModelName]: newKey,
       });
     } catch {
       // Ignore error