feat: mark-spam, rule priority persistence, run-rules-on-selected, icons fix, scheduled send + reader polish

- Mark as spam: moves mail to Spam/Junk folder of account
- Rule priority: persistPriorityOrder persists 1..N via RuleDao::update
- Run rules on selected: uses MailListView::selectedMailIds() + onRunRulesOnSelected
- Icons: switch code to qrc short aliases (close/send/bold/etc) + new detach.svg
  -> resolves all 'Cannot open file' SVG warnings at startup
- Categories: CompactMailDelegate paints category chips from CategoryDao
- Scheduled send: MailService::scheduleSend with QTimer; wire both composer paths
- Reader: show real 'Para:' recipient; delete attachment removes stored file

src/ui/rulesmanagerdialog.cpp

@@ -1,6 +1,7 @@
 #include "rulesmanagerdialog.h"
 #include "ruleditordialog.h"
 #include "db/dao/ruledao.h"
+#include "db/dao/common_structs.h"
 #include "db/dao/categorydao.h"
 #include "db/dao/folderdao.h"
 #include "services/rulesengine.h"
@@ -81,7 +82,7 @@ void RulesManagerDialog::setupUI()
             if (idx > 0) {
                 QTreeWidgetItem* prev = m_tree->takeTopLevelItem(idx);
                 m_tree->insertTopLevelItem(idx - 1, prev);
-                // TODO: update priority in DB
+                persistPriorityOrder();
             }
         });
         QAction* moveDownAct = menu.addAction(tr("Bajar prioridad"), [this, item]() {
@@ -89,7 +90,7 @@ void RulesManagerDialog::setupUI()
             if (idx < m_tree->topLevelItemCount() - 1) {
                 QTreeWidgetItem* next = m_tree->takeTopLevelItem(idx + 1);
                 m_tree->insertTopLevelItem(idx + 1, item);
-                // TODO: update priority in DB
+                persistPriorityOrder();
             }
         });
         menu.exec(m_tree->viewport()->mapToGlobal(pos));
@@ -296,3 +297,20 @@ void RulesManagerDialog::refresh()
 {
     loadRules();
 }
+
+void RulesManagerDialog::persistPriorityOrder()
+{
+    // Re-assign priority based on tree order (top = lowest number = highest priority).
+    for (int i = 0; i < m_tree->topLevelItemCount(); ++i) {
+        QTreeWidgetItem *item = m_tree->topLevelItem(i);
+        qint64 ruleId = item->data(0, Qt::UserRole).toLongLong();
+        int newPriority = i + 1;
+        item->setText(2, QString::number(newPriority));
+        auto rule = RuleDao::findById(ruleId);
+        if (rule.has_value()) {
+            Rule r = rule.value();
+            r.priority = newPriority;
+            RuleDao::update(r);
+        }
+    }
+}