Checkpoint 3: deliver playable samples and complete native authoring workflows

include/faset/editor/editor_ui.hpp

@@ -20,6 +20,8 @@ class EditorUI {
     void select_document(const std::string& document);
     const std::string& selected_entity() const;
     void select_entity(const std::string& entity);
+    bool project_switch_requested() const;
+    void set_project_switch_enabled(bool enabled);
 
   private:
     struct Impl;

include/faset/editor/mcp.hpp

@@ -23,6 +23,8 @@ class StdioTransport {
     bool closed() const noexcept {
         return closed_;
     }
+    // Write failure closes this transport; a disconnected client never exits
+    // the Editor process. A GUI can continue after closed() becomes true.
     void send(const Json& message);
 
   private:

include/faset/editor/project_launcher.hpp

@@ -0,0 +1,34 @@
+#pragma once
+#include <faset/ui/ui.hpp>
+#include <optional>
+
+namespace faset::editor {
+struct ProjectSelection {
+    std::filesystem::path path;
+    std::string name;
+    int dimension = 3;
+    bool create = false;
+};
+// Records only existing, valid projects. Call after successful Session setup.
+void remember_project(const std::filesystem::path& project);
+class ProjectLauncher {
+  public:
+    ProjectLauncher(render::Renderer&, const std::filesystem::path& engine_root,
+                    const std::filesystem::path& initial_project = {},
+                    const std::filesystem::path& recent_store = {});
+    ~ProjectLauncher();
+    void frame(const std::vector<render::Event>&);
+    const render::Snapshot& snapshot() const;
+    ui::Context& widgets();
+    const std::optional<ProjectSelection>& selection() const;
+    bool cancelled() const;
+
+  private:
+    struct Impl;
+    std::unique_ptr<Impl> impl_;
+};
+std::optional<ProjectSelection>
+run_project_launcher(const std::filesystem::path& engine_root,
+                     const std::filesystem::path& initial_project = {},
+                     std::uint64_t max_frames = 0, const std::filesystem::path& capture = {});
+} // namespace faset::editor

include/faset/editor/session.hpp

@@ -46,6 +46,8 @@ class Session {
     void register_commands();
     Json assets_list() const;
     Json jobs() const;
+    std::string source_signature() const;
+    Json schema_status() const;
     Json job(const std::string& id) const;
     void load_schema(const std::filesystem::path& path);
     void launch_player(Json scene, const std::filesystem::path& executable);
@@ -65,5 +67,9 @@ class Session {
     std::string pending_play_job_;
     Json pending_play_scene_;
     std::unique_ptr<PluginManager> plugins_;
+    std::map<std::string, std::string> submitted_sources_;
+    std::string schema_source_signature_;
+    bool schema_loaded_ = false;
+    std::string schema_error_;
 };
 } // namespace faset::editor