fix: LF line endings in deploy shell scripts (systemd 203/EXEC)

CRLF in sac-api-start.sh shebang broke sac-api with status=203/EXEC on Linux.
Add .gitattributes for *.sh and strip CR in sac-deploy before chmod.

.gitattributes

@@ -0,0 +1,2 @@
+# Shell scripts must use LF — CRLF in shebang breaks systemd (status=203/EXEC).
+*.sh text eol=lf

deploy/sac-deploy.sh

@@ -95,6 +95,7 @@ if [ -f "${APP_ROOT}/deploy/systemd/${SERVICE_NAME}.service" ]; then
 fi
 START_SH="${APP_ROOT}/deploy/systemd/sac-api-start.sh"
 if [ -f "${START_SH}" ]; then
+ sed -i 's/\r$//' "${START_SH}"
  chmod 755 "${START_SH}"
 fi