fix: strip CRLF from frontmatter block in command composition

Use rstrip('\r\n') instead of rstrip('\n') when constructing
fm_block so CRLF line endings don't leave trailing \r in the
reattached frontmatter fences.

Author: mnriem

src/specify_cli/presets.py

@@ -2463,7 +2463,7 @@ def _split_frontmatter(text: str) -> tuple:
             if fence_end == -1:
                 return None, text
 
-            fm_block = "".join(lines[:fence_end + 1]).rstrip("\n")
+            fm_block = "".join(lines[:fence_end + 1]).rstrip("\r\n")
             body = "".join(lines[fence_end + 1:])
             return fm_block, body