feat: MetalRT VLM backend + bolder screen overlay

CMakeLists.txt

@@ -103,10 +103,12 @@ add_library(rcli STATIC
     src/engines/metalrt_engine.cpp
     src/engines/metalrt_stt_engine.cpp
     src/engines/metalrt_tts_engine.cpp
+    src/engines/metalrt_vlm_engine.cpp
     src/engines/vlm_engine.cpp
     src/audio/audio_io.cpp
     src/audio/mic_permission.mm
     src/audio/camera_capture.mm
+    src/audio/camera_preview.mm
     src/audio/screen_capture.mm
     src/pipeline/orchestrator.cpp
     src/pipeline/sentence_detector.cpp
@@ -140,7 +142,7 @@ add_library(rcli STATIC
     src/api/rcli_api.cpp
 )
 
-set_source_files_properties(src/audio/mic_permission.mm src/audio/camera_capture.mm src/audio/screen_capture.mm
+set_source_files_properties(src/audio/mic_permission.mm src/audio/camera_capture.mm src/audio/camera_preview.mm src/audio/screen_capture.mm
     PROPERTIES LANGUAGE CXX)
 
 target_include_directories(rcli PUBLIC
@@ -221,6 +223,32 @@ set_target_properties(rcli_overlay PROPERTIES
     RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}"
 )
 
+# =============================================================================
+# rcli_camera_preview — standalone Cocoa helper for live camera preview window
+# =============================================================================
+add_executable(rcli_camera_preview
+    src/audio/rcli_camera_preview.m
+)
+
+set_source_files_properties(src/audio/rcli_camera_preview.m PROPERTIES LANGUAGE CXX)
+
+target_compile_options(rcli_camera_preview PRIVATE -x objective-c++)
+
+target_link_libraries(rcli_camera_preview PRIVATE
+    "-framework AppKit"
+    "-framework AVFoundation"
+    "-framework CoreMedia"
+    "-framework CoreVideo"
+    "-framework CoreImage"
+    "-framework ImageIO"
+    "-framework UniformTypeIdentifiers"
+)
+
+set_target_properties(rcli_camera_preview PROPERTIES
+    OUTPUT_NAME "rcli_camera_preview"
+    RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}"
+)
+
 # =============================================================================
 # rcli_test — test executable
 # =============================================================================

Formula/rcli.rb

@@ -12,6 +12,7 @@ class Rcli < Formula
   def install
     bin.install "bin/rcli"
     bin.install "bin/rcli_overlay" if File.exist? "bin/rcli_overlay"
+    bin.install "bin/rcli_camera_preview" if File.exist? "bin/rcli_camera_preview"
     lib.install Dir["lib/*.dylib"]
   end
 

install.sh

@@ -70,6 +70,7 @@ else
     mkdir -p "$CELLAR/bin" "$CELLAR/lib" 2>/dev/null || sudo mkdir -p "$CELLAR/bin" "$CELLAR/lib"
     cp "$WORKDIR"/rcli-*/bin/rcli "$CELLAR/bin/" 2>/dev/null || sudo cp "$WORKDIR"/rcli-*/bin/rcli "$CELLAR/bin/"
     cp "$WORKDIR"/rcli-*/bin/rcli_overlay "$CELLAR/bin/" 2>/dev/null || sudo cp "$WORKDIR"/rcli-*/bin/rcli_overlay "$CELLAR/bin/" 2>/dev/null || true
+    cp "$WORKDIR"/rcli-*/bin/rcli_camera_preview "$CELLAR/bin/" 2>/dev/null || sudo cp "$WORKDIR"/rcli-*/bin/rcli_camera_preview "$CELLAR/bin/" 2>/dev/null || true
     cp "$WORKDIR"/rcli-*/lib/*.dylib "$CELLAR/lib/" 2>/dev/null || sudo cp "$WORKDIR"/rcli-*/lib/*.dylib "$CELLAR/lib/"
 
     brew link --overwrite "$FORMULA" 2>/dev/null || sudo brew link --overwrite "$FORMULA"

scripts/package.sh

@@ -27,6 +27,10 @@ if [ -f "$BUILD_DIR/rcli_overlay" ]; then
     cp "$BUILD_DIR/rcli_overlay" "$DIST_DIR/bin/rcli_overlay"
     echo "  + bin/rcli_overlay"
 fi
+if [ -f "$BUILD_DIR/rcli_camera_preview" ]; then
+    cp "$BUILD_DIR/rcli_camera_preview" "$DIST_DIR/bin/rcli_camera_preview"
+    echo "  + bin/rcli_camera_preview"
+fi
 
 # --- Collect dylibs ---
 DYLIBS=(
@@ -155,6 +159,9 @@ codesign --force --sign - "$BINARY"
 if [ -f "$DIST_DIR/bin/rcli_overlay" ]; then
     codesign --force --sign - "$DIST_DIR/bin/rcli_overlay"
 fi
+if [ -f "$DIST_DIR/bin/rcli_camera_preview" ]; then
+    codesign --force --sign - "$DIST_DIR/bin/rcli_camera_preview"
+fi
 for lib in "$DIST_DIR/lib/"*.dylib; do
     codesign --force --sign - "$lib"
 done