chore(boxed): stop tracking Windows agent installers, ignore them

.gitignore

@@ -0,0 +1,5 @@
+# Windows agent installers are published to boxed/ by the edon-agent-windows
+# build and served from disk; keep the (large, frequently rebuilt) binaries out
+# of git history. Other boxed/ artifacts (.deb, .rpm, restic, checksums) stay tracked.
+/boxed/edon-agent-setup-*.exe
+/boxed/edon-agent-win64.exe

boxed/edon-agent-win64.exe

@@ -1 +0,0 @@
-edon-agent-setup-0.1.0.exe