fix: use read_bytes/write_bytes for platform-stable EOL handling

Address Copilot review: avoid platform newline translation by using
read_bytes()/write_bytes() instead of read_text()/write_text() when
post-processing SKILL.md files for argument-hint injection.

Author: Quratulain-bilal

src/specify_cli/integrations/claude/__init__.py

@@ -142,9 +142,10 @@ def setup(
             if not hint:
                 continue
 
-            content = path.read_text(encoding="utf-8")
+            content_bytes = path.read_bytes()
+            content = content_bytes.decode("utf-8")
             updated = self.inject_argument_hint(content, hint)
             if updated != content:
-                path.write_text(updated, encoding="utf-8")
+                path.write_bytes(updated.encode("utf-8"))
 
         return created