Add right-click menu to reorder or unpin favs

Right-clicking a fav tile now opens a small
context menu with Move left, Move right, and
Unpin, instead of relying on drag-only reorder.

- speeddial.js: oncontextmenu handler, the
  menu build/position/dismiss logic, and an
  Escape-key close.
- style.css: .ctx-menu/.ctx-item styling.
- ActionRegistry: reorder_favourites persists
  the new bar order to AppConfig.
- SpeedDialDialog: routes the new
  reorder_favourites command from the page.

src/slic3r/GUI/ActionRegistry.cpp

@@ -254,6 +254,23 @@ void ActionRegistry::set_favourite(const std::string& id, bool on)
         live->favourite = on;
 }
 
+void ActionRegistry::reorder_favourites(const std::vector<std::string>& ids)
+{
+    assert(wxThread::IsMain());
+    auto cur = read_string_array("favourite_actions");
+    std::vector<std::string> next;
+    // keep the requested order, but only ids that are actually favourites (guard a bad payload)
+    for (const auto& id : ids)
+        if (std::find(cur.begin(), cur.end(), id) != cur.end() &&
+            std::find(next.begin(), next.end(), id) == next.end())
+            next.push_back(id);
+    // why: don't drop favourites the page omitted (e.g. pins with no live action hidden from the bar)
+    for (const auto& id : cur)
+        if (std::find(next.begin(), next.end(), id) == next.end())
+            next.push_back(id);
+    write_section("favourite_actions", nlohmann::json(next));
+}
+
 bool ActionRegistry::should_ask(const std::string& plugin_key) const
 {
     assert(wxThread::IsMain());

src/slic3r/GUI/ActionRegistry.hpp

@@ -58,6 +58,7 @@ public:
     // Dispatch + write-through (registry is the only thing that touches AppConfig).
     ScriptRunOutcome run(const std::string& id);            // runs + bumps stats
     void             set_favourite(const std::string& id, bool on);
+    void             reorder_favourites(const std::vector<std::string>& ids);   // persist a new bar order
 
     bool should_ask(const std::string& plugin_key) const;   // run-confirm gate
     void suppress_ask(const std::string& plugin_key);

src/slic3r/GUI/SpeedDialDialog.cpp

@@ -189,6 +189,12 @@ private:
             send_actions();
         }
         else if (cmd == "toggle_favourite") wxGetApp().action_registry().set_favourite(p.value("id", ""), p.value("fav", false));
+        else if (cmd == "reorder_favourites") {
+            std::vector<std::string> ids;
+            if (p.contains("ids") && p["ids"].is_array())
+                for (auto& e : p["ids"]) if (e.is_string()) ids.push_back(e.get<std::string>());
+            wxGetApp().action_registry().reorder_favourites(ids);
+        }
         else if (cmd == "run_action")       run_action(p.value("id", ""), p.value("title", ""));
         else if (cmd == "resize")           resize_to_content(json_int_or(p, "height", 0));
         else if (cmd == "close_page")       Dismiss();