backend-infra-engineer: Post v0.3.9-hotfix7 snapshot (build cleanup)

docs/internal/plans/ui-infrastructure-proposals.md

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+# UI Infrastructure Technical Improvement Proposals
+
+These proposals address the infrastructure changes needed to support the YAZE Design Language.
+
+## Proposal A: Unified Panel System
+**Problem:** `PanelManager` currently has hardcoded logic for specific panels, making it hard for users to create custom layouts or for plugins to register new views.
+
+**Solution:** Refactor `PanelManager` to use a Registry pattern.
+
+```cpp
+// Concept
+struct PanelDef {
+    std::string id;
+    std::string display_name;
+    std::function<void()> draw_fn;
+    PanelCategory category; // Editor, Debug, Agent
+    ImGuiDir default_dock; // Left, Bottom, Center
+};
+
+PanelRegistry::Register("dungeon_properties", { ... });
+```
+
+**Benefit:** Allows the `LayoutManager` to generically save/restore *any* panel's open state and position without hardcoded checks.
+
+## Proposal B: Theme Abstraction Layer Refactor
+**Problem:** `src/app/gui/core/style.cc` contains `ColorsYaze()` with hardcoded definitions (e.g., `alttpDarkGreen`).
+
+**Solution:**
+1.  Deprecate `ColorsYaze`.
+2.  Expand `EnhancedTheme` to include a "Game Palette" section (e.g., `GameCol_LinkGreen`, `GameCol_GanonBlue`).
+3.  Update `ThemeManager` to populate these from configuration files (JSON/TOML), allowing users to "skin" the editor to look like different Zelda games (e.g., Minish Cap style).
+
+## Proposal C: Layout Persistence Engine
+**Problem:** Layouts are currently stuck in `imgui.ini` (binary/opaque to user) or hardcoded presets.
+
+**Solution:**
+1.  Create a `LayoutService` that wraps `ImGui::SaveIniSettingsToMemory`.
+2.  Allow users to "Save Current Layout As..." which writes the INI data to a named file in `user/layouts/`.
+3.  Add a "Reset Layout" command that forces a reload of the default preset for the current context.
+
+## Proposal D: Input Widget Standardization
+**Problem:** Scroll wheel support on Hex inputs is inconsistent.
+
+**Solution:**
+Modify `src/app/gui/core/input.cc`:
+
+```cpp
+bool InputHexByte(const char* label, uint8_t* v) {
+    // ... existing input logic ...
+    if (ImGui::IsItemHovered()) {
+        float wheel = ImGui::GetIO().MouseWheel;
+        if (wheel != 0) {
+            if (wheel > 0) *v += 1; else *v -= 1;
+            return true;
+        }
+    }
+    return false;
+}
+```
+
+## Proposal E: State Management Audit
+**Problem:** `ActivityBar` and `StatusBar` often hold their own state or read global statics.
+
+**Solution:**
+*   **Context Injection:** UI components should receive a `EditorContext*` or `ProjectState*` in their `Draw()` method rather than accessing singletons.
+*   **Reactive UI:** Implement a simple `EventBus` for UI updates (e.g., `Event::ProjectLoaded`, `Event::SelectionChanged`) so the Status Bar updates only when necessary, rather than polling every frame.