fix(core): correct filename sanitization regex and cleanup

- Adjust regex to replace semicolon only with spacer
- Remove colon from characters replaced by spacer, handle as removal instead
- Comment out removal of extra neighbouring spacers to prevent unintended collapses
- Refine unsafe characters removal pattern to avoid filename issues

unshackle/core/utilities.py

@@ -99,9 +99,9 @@ def sanitize_filename(filename: str, spacer: str = ".") -> str:
     # remove or replace further characters as needed
     filename = "".join(c for c in filename if unicodedata.category(c) != "Mn")  # hidden characters
     filename = filename.replace("/", " & ").replace(";", " & ")  # e.g. multi-episode filenames
-    filename = re.sub(r"[:; ]", spacer, filename)  # structural chars to (spacer)
-    filename = re.sub(r"[\\*!?¿,'\"" "()<>|$#~]", "", filename)  # not filename safe chars
-    filename = re.sub(rf"[{spacer}]{{2,}}", spacer, filename)  # remove extra neighbouring (spacer)s
+    filename = re.sub(r"[;]", spacer, filename)  # structural chars to (spacer)
+    filename = re.sub(r"[\\:*!?¿,'\"""<>|$#~]", "", filename)  # not filename safe chars
+    # filename = re.sub(rf"[{spacer}]{{2,}}", spacer, filename)  # remove extra neighbouring (spacer)s
 
     return filename