Plugins: prop hunt APIs, and plugin commands in the console lookup

- reskate.entities.blueprints lists the game's object blueprints (meshes only if asked),
  and reskate.entities.bounds gives a blueprint's box, so a mod can pick a prop by list or at random
- Attached objects take upright, turn and ground (a floor found within reach below), the "root"
  joint, and a 6th options argument with solid; spawned props' bodies are found and ghosted
- reskate.skater.hide, reskate.world.pick, and skater.get gives right and switch
- reskate.console.command takes an optional 4th table of subcommands; the console lookup
  suggests plugin commands word by word, and plugin commands lists the subcommands
- objbody: a test command for finding which body setter takes a prop out of collision

Extension/Plugins/plugin_runtime.cpp

@@ -454,9 +454,10 @@ std::string list_commands() {
     std::string text;
     const auto add = [&](const std::vector<Status>& all, std::string_view suffix) {
         for (const auto& plugin : all)
-            for (const auto& [name, help] : plugin.commands) {
+            for (const auto& command : plugin.commands) {
                 if (!text.empty()) text += '\n';
-                text += std::format("{} - {} ({}{})", name, help, plugin.id, suffix);
+                text += std::format("{}{}{} - {} ({}{})", command.name, command.args.empty() ? "" : " ", command.args, command.help, plugin.id,
+                                    suffix);
             }
     };
     add(host->status(), "");
@@ -464,6 +465,26 @@ std::string list_commands() {
     return text.empty() ? "No plugin has a console command." : text;
 }
 
+std::vector<CommandHint> command_hints() {
+    static std::vector<CommandHint> hints;
+    static std::uint64_t next{};
+    const auto now = GetTickCount64();
+    if (now < next) return hints;
+    next = now + 500;
+    hints.clear();
+    if (!host) return hints;
+    const auto add = [&](const std::vector<Status>& all, std::string_view suffix) {
+        for (const auto& plugin : all)
+            for (const auto& command : plugin.commands)
+                if (std::none_of(hints.begin(), hints.end(), [&](const auto& hint) { return hint.name == command.name; }))
+                    hints.push_back({command.name, command.args, command.help, plugin.id + std::string(suffix)});
+    };
+    add(host->status(), "");
+    if (serving) add(server_host->status(), "@server");
+    std::sort(hints.begin(), hints.end(), [](const auto& a, const auto& b) { return a.name < b.name; });
+    return hints;
+}
+
 // "<id>@server" names a server copy (on this game while it hosts a lobby); a plain id, the player's copy.
 namespace {
 template <class Do> std::string either(std::string_view id, Do&& act) {