docs: fix stale '_vectorapi_*' collection names in store doc comments

src/key_store.hpp

@@ -9,7 +9,7 @@
 
 namespace svapi {
 
-/// DB-backed store for API keys, held in collection `_vectorapi_keys`.
+/// DB-backed store for API keys, held in collection `vectorapi_keys`.
 /// All reads are served from an in-memory snapshot that is refreshed after
 /// every write and optionally kept live via `startWatch()`.
 class KeyStore {

src/settings_store.hpp

@@ -7,7 +7,7 @@
 
 namespace svapi {
 
-/// DB-backed global settings store (single document in `_vectorapi_settings`).
+/// DB-backed global settings store (single document in `vectorapi_settings`).
 /// Reads are served from a mutex-guarded shared_ptr snapshot.
 class SettingsStore {
 public: