Add project files (part 1/2)

Co-Authored-By: Claude Sonnet 5 <[email protected]>

injector/build-linux.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+# Build slinky-inject for the host Linux.
+set -e
+cd "$(dirname "$0")"
+cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
+cmake --build build -j"$(nproc)"
+echo "built: $(pwd)/build/slinky-inject"