fix(assets): skip missing binary assets with warning instead of failing

asset_packer now emits a zero-size empty stub for BINARY assets whose
file is not found, and continues with a warning rather than aborting.
Allows building without optional assets like cnn_v2_weights.bin.

handoff(Gemini): asset_packer tolerates missing BINARY files; GetAsset()
returns nullptr/size=0 for those assets at runtime.

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

1 files changed, 10 insertions, 3 deletions

diff --git a/tools/asset_packer.cc b/tools/asset_packer.cc
index 37d2a57..deb4de5 100644
--- a/tools/asset_packer.cc
+++ b/tools/asset_packer.cc
@@ -508,9 +508,16 @@ int main(int argc, char* argv[]) {
         } else {
           std::ifstream asset_file(full_path, std::ios::binary);
           if (!asset_file.is_open()) {
-            fprintf(stderr, "Error: Could not open asset file: %s\n",
-                    full_path.c_str());
-            return 1;
+            fprintf(stderr,
+                    "Warning: Asset file not found, skipping: %s (%s)\n",
+                    info.name.c_str(), full_path.c_str());
+            fprintf(assets_data_cc_file,
+                    "const size_t ASSET_SIZE_%s = 0;\n",
+                    info.name.c_str());
+            fprintf(assets_data_cc_file,
+                    "alignas(16) static const uint8_t %s[] = {0};\n",
+                    info.data_array_name.c_str());
+            continue;
           }
           buffer.assign((std::istreambuf_iterator<char>(asset_file)),
                         std::istreambuf_iterator<char>());