perf(mister): improve Core-backed browsing performance

cmake/ZaparooRust.cmake

@@ -83,6 +83,8 @@ endif()
 qt_add_executable(
     frontend
     "${CMAKE_SOURCE_DIR}/src/app/main.cpp"
+    "${CMAKE_SOURCE_DIR}/src/app/frontend_arguments.h"
+    "${CMAKE_SOURCE_DIR}/src/app/frontend_arguments.cpp"
     "${CMAKE_SOURCE_DIR}/src/app/media_image_provider.h"
     "${CMAKE_SOURCE_DIR}/src/app/media_image_provider.cpp"
     "${CMAKE_SOURCE_DIR}/src/app/tinted_svg_image_provider.h"

docs/architecture.md

@@ -20,7 +20,7 @@ src/app/main.cpp
     │     │     impl for QML singletons (sync seed + qt_thread watcher).
     │     │
     │     ├── src/mister_runtime.rs
-    │     │     Pre-Qt setup on ARM32: vmode resolution switch, zaparoo.sh start.
+    │     │     Pre-Qt ARM32 setup: automatic framebuffer sizing, zaparoo.sh start.
     │     │     Compiled on all platforms; MiSTer-specific calls are gated by cfg.
     │     │
     │     ├── src/models/  [Zaparoo.Browse QML module via cxx-qt 0.8]

rust/frontend/src/lib.rs

@@ -376,12 +376,10 @@ pub extern "C" fn zaparoo_rust_init(crt_native_path_forced: bool) -> c_int {
 
     // CRT path always renders to one of the native writer's mode
     // geometries (352x240 NTSC, 352x288 PAL, 720x480 480i), selected by
-    // the persisted video standard. User-configured [video] dimensions
-    // still apply to the normal MiSTer path, but `--crt` overrides them
-    // so startup `vmode`, the desktop preview canvas, and the writer's
-    // fb0 validation all agree. frontend.toml is the durable source for
-    // the standard and offsets (state.toml lives on tmpfs on MiSTer and
-    // mirrors it).
+    // the persisted video standard. Digital MiSTer ignores user-configured
+    // [video] dimensions and resolves an automatic framebuffer size below.
+    // frontend.toml remains the durable source for CRT standard and offsets
+    // (state.toml lives on tmpfs on MiSTer and mirrors it).
     if crt_native_path_forced {
         let standard = zaparoo_core::config::normalize_crt_video_standard(
             config.settings.crt_video_standard.as_deref().unwrap_or(""),
@@ -396,6 +394,7 @@ pub extern "C" fn zaparoo_rust_init(crt_native_path_forced: bool) -> c_int {
         let _ = CRT_H_OFFSET.set(h_offset);
         let _ = CRT_V_OFFSET.set(v_offset);
     }
+    mister_runtime::resolve_video_size(&mut config, crt_native_path_forced);
 
     // Cache the language override so `zaparoo_rust_language_code` (called
     // from main.cpp before the QML engine loads) can return it without