fix: tray main-thread message loop, numpy <2.0 pin, installer config copy

- Rewrite tray to run on main thread (pystray owns message loop, uvicorn
  in background thread) — fixes unresponsive confirmation dialogs
- Use native Windows MessageBoxW instead of tkinter (embedded Python
  has no tkinter)
- Pin numpy <2.0 to fix soundcard's numpy.fromstring (removed in 2.0)
- Strip transitive numpy 2.x wheels in build script
- Installer copies config.example.yaml as config.yaml on fresh install
- Suppress noisy screen_brightness_control warnings

build-dist-windows.sh

@@ -74,17 +74,24 @@ WIN_DEPS=(
 # Visualizer dependencies
 VIS_DEPS=(
     "soundcard>=0.4.0"
-    "numpy>=1.24.0"
+    "numpy>=1.24.0,<2.0"
 )
 
 ALL_DEPS=("${CORE_DEPS[@]}" "${WIN_DEPS[@]}" "${VIS_DEPS[@]}")
 
 for dep in "${ALL_DEPS[@]}"; do
-    pip download --quiet --dest "$WHEEL_DIR" \
+    pip download --quiet --no-cache-dir --dest "$WHEEL_DIR" \
         --platform win_amd64 --python-version "${PYTHON_SHORT}" \
         --implementation cp --only-binary :all: \
         "$dep" 2>/dev/null || \
-    pip download --quiet --dest "$WHEEL_DIR" "$dep"
+    pip download --quiet --no-cache-dir --dest "$WHEEL_DIR" \
+        --python-version "${PYTHON_SHORT}" \
+        "$dep"
+done
+
+# Remove numpy 2.x wheels pulled as transitive deps (soundcard requires <2.0)
+for f in "$WHEEL_DIR"/numpy-2*; do
+    [ -f "$f" ] && echo "Removing incompatible: $(basename "$f")" && rm "$f"
 done
 
 # Install wheels into site-packages