fix(bbcode): fix ReDos vulnerabilities in BBCodeService (#96)

* fix(bbcode): fix ReDos of imagemap parsing

* fix(bbcode): use `regex` and add timeout to avoid too long time to parse

* feat(bbcode): use `make_tag` to generate HTML tags

* docs(bbcode): add docstrings for BBCodeService

* fix(user): validate BBCode content before processing userpage update

* fix(bbcode): catch timeout errors in BBCode parsing with MaliciousBBCodeError

* fix(bbcode): resolve reviews

* fix(bbcode): use `make_tag` in `_parse_size`

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix(bbcode): fix using `make_tag` in `_parse_size`

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

app/models/userpage.py

@@ -98,3 +98,12 @@ class ForbiddenTagError(UserpageError):
         message = f"Forbidden tag '{tag}' is not allowed."
         super().__init__(message, "forbidden_tag")
         self.tag = tag
+
+
+class MaliciousBBCodeError(UserpageError):
+    """恶意BBCode错误"""
+
+    def __init__(self, detail: str):
+        message = f"Malicious BBCode detected: {detail}"
+        super().__init__(message, "malicious_bbcode")
+        self.detail = detail