docs(init): add glfw as macOS brew dependency

project_init.sh now checks/installs both wgpu-native and glfw via brew.
HOWTO.md documents the macOS prerequisites before the build steps.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

2 files changed, 17 insertions, 8 deletions

diff --git a/doc/HOWTO.md b/doc/HOWTO.md
index bfb47fd..e44978d 100644
--- a/doc/HOWTO.md
+++ b/doc/HOWTO.md
@@ -6,6 +6,13 @@ Quick reference for common tasks.
 
 ## Building
 
+### macOS Prerequisites
+
+```bash
+brew install wgpu-native glfw
+./scripts/project_init.sh   # fetches miniaudio, glfw3webgpu
+```
+
 ### Workspace Selection
 ```bash
 # Main demo (default)
diff --git a/scripts/project_init.sh b/scripts/project_init.sh
index 549e146..5a6ac28 100755
--- a/scripts/project_init.sh
+++ b/scripts/project_init.sh
@@ -24,16 +24,18 @@ else
   echo "glfw3webgpu already present."
 fi
 
-# Check for wgpu-native (system install)
+# Check for brew dependencies (macOS)
 if command -v brew >/dev/null 2>&1; then
-  if ! brew list wgpu-native >/dev/null 2>&1; then
-    echo "Warning: wgpu-native not found via brew. Installing..."
-    brew install wgpu-native
-  else
-    echo "wgpu-native found (via brew)."
-  fi
+  for pkg in wgpu-native glfw; do
+    if ! brew list "$pkg" >/dev/null 2>&1; then
+      echo "Warning: $pkg not found via brew. Installing..."
+      brew install "$pkg"
+    else
+      echo "$pkg found (via brew)."
+    fi
+  done
 else
-  echo "Warning: Homebrew not found. Ensure wgpu-native is installed manually."
+  echo "Warning: Homebrew not found. Ensure wgpu-native and glfw are installed manually."
 fi
 
 echo "Done."