add binary build workflow and hook policy

hook.sh

@@ -1,5 +1,16 @@
 #!/bin/sh
-# Default simplegit hook policy. Deployments can replace it with -hook-script.
-# $1 is the Git hook type, $2 is the owner/name repository, remaining arguments
-# are the original Git hook arguments. Original stdin and GIT_* env are intact.
+# Default standalone policy: append the hook invocation and its stdin to a log.
+# Integrations can supply another script with simplegit daemon -hook-script.
+
+log_file=${SIMPLEGIT_HOOK_LOG:-${SIMPLEGIT_REPO_ROOT%/repos}/hooks.log}
+{
+  printf '%s\t%s\t%s' "$(date -u +%Y-%m-%dT%H:%M:%SZ)" "$1" "$2"
+  shift 2
+  for arg in "$@"; do
+    printf '\t%s' "$arg"
+  done
+  printf '\n'
+  sed 's/^/stdin\t/'
+} >>"$log_file" 2>/dev/null || true
+
 exit 0