Memos layers #tag syntax on top of CommonMark, but there was no way to
write a literal "#NAS" — it always became a clickable tag (issue #6035).
Handle escapes lexically, the way TipTap/prosemirror-markdown do, with no
"escaped tag" node in the document model:
- Parse: marked's built-in backslash escape already turns "\#NAS" into
plain text; the read-only renderer (remark-tag) now honors the same
escape by lexing from the original source slice and falling back to the
prior value-based parse when it can't faithfully reconstruct the text.
- Serialize: a tag-aware Markdown extension (tagMarkdown.ts) backslash-
escapes a "#" that would re-parse into a tag, skipping links and code
where tags never form.
- The editor's #tag lexing moves to the canonical @tiptap/markdown
markdownTokenizer; tag-in-link skipping moves to a tree pass so the
editor and renderer agree.
The capped tag-run grammar is consolidated into utils/tag-grammar.ts
(TAG_RUN), shared by the tokenizer, the serialize-escape, and the
renderer so they can't drift. README documents why the markdown manager
is worked around in three places.
