Send optional document metadata with KOSync progress uploads

lib/I18n/translations/english.yaml

@@ -170,6 +170,7 @@ STR_FILENAME: "Filename"
 STR_BINARY: "Binary"
 STR_MENU_KOSYNC_BEHAVIOR: "Sync Behavior"
 STR_KO_SYNC_ON_BOOK_CLOSE: "Auto-Push on Book Close"
+STR_SEND_METADATA: "Send Document Metadata"
 STR_KO_AUTO_SYNC_SKIPPED: "Remote ahead, skipping"
 STR_KO_LONGPRESS_HINT: "Hold Confirm to open with sync"
 STR_SET_CREDENTIALS_FIRST: "Set credentials first"

lib/KOReaderSync/KOReaderCredentialStore.cpp

@@ -175,3 +175,8 @@ void KOReaderCredentialStore::setMatchMethod(DocumentMatchMethod method) {
   matchMethod = method;
   LOG_DBG("KRS", "Set match method: %s", method == DocumentMatchMethod::FILENAME ? "Filename" : "Binary");
 }
+
+void KOReaderCredentialStore::setSendMetadata(bool value) {
+  sendMetadata = value;
+  LOG_DBG("KRS", "Send metadata: %s", value ? "enabled" : "disabled");
+}

lib/KOReaderSync/KOReaderCredentialStore.h

@@ -27,6 +27,7 @@ class KOReaderCredentialStore {
   std::string password;
   std::string serverUrl;                                            // Custom sync server URL (empty = default)
   DocumentMatchMethod matchMethod = DocumentMatchMethod::FILENAME;  // Default to filename for compatibility
+  bool sendMetadata = false;
 
   // Private constructor for singleton
   KOReaderCredentialStore() = default;
@@ -72,6 +73,10 @@ class KOReaderCredentialStore {
   // Document matching method
   void setMatchMethod(DocumentMatchMethod method);
   DocumentMatchMethod getMatchMethod() const { return matchMethod; }
+
+  // Send document metadata (filename, title, authors) with progress uploads
+  void setSendMetadata(bool value);
+  bool getSendMetadata() const { return sendMetadata; }
 };
 
 // Helper macro to access credential store

lib/KOReaderSync/KOReaderSyncClient.cpp

@@ -555,6 +555,13 @@ KOReaderSyncClient::Error KOReaderSyncClient::updateProgress(const KOReaderProgr
   doc["device"] = DEVICE_NAME;
   doc["device_id"] = DEVICE_ID;
 
+  if (progress.metadata) {
+    JsonObject meta = doc["metadata"].to<JsonObject>();
+    meta["filename"] = progress.metadata->filename;
+    meta["title"] = progress.metadata->title;
+    meta["authors"] = progress.metadata->authors;
+  }
+
   std::string body;
   serializeJson(doc, body);
 

lib/KOReaderSync/KOReaderSyncClient.h

@@ -1,16 +1,29 @@
 #pragma once
+#include <optional>
 #include <string>
 
+/**
+ * Optional document metadata sent alongside progress uploads.
+ * Only populated when KOReaderCredentialStore::getSendMetadata() is true.
+ * The official sync server ignores this field; custom servers may use it.
+ */
+struct KOReaderMetadata {
+  std::string filename;
+  std::string title;
+  std::string authors;
+};
+
 /**
  * Progress data from KOReader sync server.
  */
 struct KOReaderProgress {
-  std::string document;  // Document hash
-  std::string progress;  // XPath-like progress string
-  float percentage;      // Progress percentage (0.0 to 1.0)
-  std::string device;    // Device name
-  std::string deviceId;  // Device ID
-  int64_t timestamp;     // Unix timestamp of last update
+  std::string document;                      // Document hash
+  std::string progress;                      // XPath-like progress string
+  float percentage;                          // Progress percentage (0.0 to 1.0)
+  std::string device;                        // Device name
+  std::string deviceId;                      // Device ID
+  int64_t timestamp;                         // Unix timestamp of last update
+  std::optional<KOReaderMetadata> metadata;  // Optional document metadata
 };
 
 /**