[PM-26681] - ensure initial cipher state is set for empty vaults (#16793)

* don't skip cipher state updates for empty vaults

* add specs and comment

* do not return ciphers, just return

* update spec names

libs/common/src/vault/services/cipher.service.ts

@@ -1169,8 +1169,10 @@ export class CipherService implements CipherServiceAbstraction {
     // If stored and provided data are identical, this event doesn’t fire and the ciphers$
     // observable won’t emit a new value. In this case we can skip the update to avoid calling
     // clearCache and causing an empty state.
-    if (JSON.stringify(current) === JSON.stringify(ciphers)) {
-      return ciphers;
+    // If the current state is empty (eg. for new users), we still want to perform the update to ensure
+    // we trigger an emission as many subscribers rely on it during initialization.
+    if (Object.keys(current).length > 0 && JSON.stringify(current) === JSON.stringify(ciphers)) {
+      return;
     }
 
     await this.updateEncryptedCipherState(() => ciphers, userId);