fix(key-server): handle missing keys consistently

- normalize 404 and empty responses as plain not-found results
- distinguish missing keys from transport failures in publication checks
- add key-server not-found helpers and unit coverage
- disable batch actions for key groups and empty targets
- add publish and refresh actions to the key manager menu
- reformat affected C++ declarations and callbacks

1 files changed, 7 insertions, 0 deletions

diff --git a/src/m_key_server_sync/KeyServerBatchLogic.h b/src/m_key_server_sync/KeyServerBatchLogic.h
index 439ef87..60ea682 100644
--- a/src/m_key_server_sync/KeyServerBatchLogic.h
+++ b/src/m_key_server_sync/KeyServerBatchLogic.h
@@ -68,6 +68,13 @@ auto Normalise(const std::optional<BatchKey>& key,
  */
 auto JoinForImport(const QList<QByteArray>& blocks) -> QByteArray;
 
+/// What a lookup failure says when the server simply does not have the key:
+/// not an error, and never the transport's own wording.
+auto NotFoundText() -> QString;
+
+/// Whether @p error is NotFoundText().
+auto IsNotFound(const QString& error) -> bool;
+
 /// What a finished refresh says, e.g. "3 of 4 keys fetched" plus failures.
 auto RefreshSummary(int fetched, int total, const QStringList& failures)
     -> QString;