feat: media_async + media_index modules, media_files table, tests

- media_async: thread-per-task async engine with primitives (sha256, sign, copy, uuid, file_size)
- media_index: media_files DB table with register_async for indexing chunks
- chat_msg: async media submission via register_async, simplified chat_msg_submit fields
- voice_recorder/attachment_sender: write single file (no chunk splitting on caller side)
- inputbar/messagelist: updated to new simplified submit interface
- test_media_async: 4-thread stress test (200K ops / 2 sec, 0 errors)
- test_media_index: 9 cases covering commit edge cases + async flow
- build: Makefile.am, CMakeLists.txt, utun_sources.cmake updated

tools/chatgui/src/settingsdialog.cpp

@@ -6,6 +6,7 @@
 #include "nodespage.h"
 #include "soundsettingspage.h"
 #include "audiodevicesettingspage.h"
+#include "storagesettingspage.h"
 #include "../transport/gui_bridge.h"
 #include "../../lib/mem.h"
 #include "../db/db_manager.h"
@@ -45,6 +46,7 @@ SettingsDialog::SettingsDialog(const QString& configPath, DbManager* db, UtunNod
         "QListWidget::item { padding: 10px 14px; }"
         "QListWidget::item:selected { background: #3390EC; color: white; }");
     m_categoryList->addItem("Profile");
+    m_categoryList->addItem("Storage");
     m_categoryList->addItem("Network");
     m_categoryList->addItem("Database");
     m_categoryList->addItem("Status");
@@ -84,6 +86,10 @@ SettingsDialog::SettingsDialog(const QString& configPath, DbManager* db, UtunNod
     profLayout->addRow(sortLabel, m_sortCombo);
     m_pages->addWidget(profilePage);
 
+    // Storage page
+    m_storagePage = new StorageSettingsPage(db, m_pages);
+    m_pages->addWidget(m_storagePage);
+
     // Network page
     m_networkPage = new NetworkSettingsPage(m_pages);
     m_pages->addWidget(m_networkPage);
@@ -166,11 +172,12 @@ void SettingsDialog::loadProfileFromConfig(const QString& path) {
 
 void SettingsDialog::onCategoryChanged(int row) {
     m_pages->setCurrentIndex(row);
-    if (row == 2) m_databasePage->refreshStatus();
-    if (row == 3) m_statusPage->refreshStatus();
-    if (row == 4) m_nodesPage->refreshNodes();
-    if (row == 5) m_soundPage->loadFromDb();
-    if (row == 6) m_audioDevicePage->loadFromDb();
+    if (row == 1) m_storagePage->loadFromDb();
+    if (row == 3) m_databasePage->refreshStatus();
+    if (row == 4) m_statusPage->refreshStatus();
+    if (row == 5) m_nodesPage->refreshNodes();
+    if (row == 6) m_soundPage->loadFromDb();
+    if (row == 7) m_audioDevicePage->loadFromDb();
 }
 
 void SettingsDialog::onSave() {
@@ -227,5 +234,6 @@ void SettingsDialog::onSave() {
 
     m_soundPage->applyAndSave();
     m_audioDevicePage->applyAndSave();
+    m_storagePage->applyAndSave();
     accept();
 }