fix(wasm): OOM on low-memory devices — revert to 256MB + growth (#29)

INITIAL_MEMORY=1GB caused immediate OOM abort on mobile and
low-memory devices. Revert to 256MB initial with ALLOW_MEMORY_GROWTH=1.
The pthreads+growth warning is a minor perf note, not a crash.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: unamedkr

wasm/build.sh

@@ -24,9 +24,9 @@ emcc "$SCRIPT_DIR/quant_wasm.c" \
     -flto \
     -pthread \
     -s WASM=1 \
-    -s INITIAL_MEMORY=1GB \
+    -s INITIAL_MEMORY=256MB \
     -s MAXIMUM_MEMORY=4GB \
-    -s ALLOW_MEMORY_GROWTH=0 \
+    -s ALLOW_MEMORY_GROWTH=1 \
     -s EXPORTED_FUNCTIONS='["_main","_wasm_load_model","_wasm_generate","_wasm_generate_async","_wasm_model_info","_wasm_is_ready","_malloc","_free"]' \
     -s EXPORTED_RUNTIME_METHODS='["UTF8ToString","allocateUTF8","FS"]' \
     -s FORCE_FILESYSTEM=1 \