[iamnbutler]

Timeline text now renders as written for bare URLs ending in ), $-containing text, and [text] without a link target. This extends the chat comark plugin from #239.

Root causes (comark 0.3.2):

• createParse({ autoClose: true }) runs autoCloseMarkdown, which counts markers on the last line and appends a guessed closer. In Foo_(bar) the _ is preceded by a word character but followed by (, so it counts as an unclosed italic and gets _ appended. A lone $ counts as unclosed inline math and gets $ appended (${tpl} → ${tpl}$, cost $5 today → cost $5 today$). It can also append ], ), **, ~~, and `. Ace's parser now sets autoClose: false. During streaming, an unclosed marker such as **bol shows as literal text until its closer arrives. markdown-it already ends unclosed code fences at the end of the input.
• comark's MDC comark_inline_span rule turns [text] into a span when no (url) or [ref] follows, so the brackets disappear. The chat plugin now disables it along with comark_inline_props.

Parse output changes, so VERSION goes from 8 to 9.

Fixes #244

Verification

I ran the real parseSegments from a scratch script outside the repo and deleted it afterwards. OffscreenCanvas was stubbed for text measurement only.

• https://en.wikipedia.org/wiki/Foo_(bar) (alone and mid-sentence): link and text no longer get a trailing _
• ${tpl} and cost $5 today: no trailing $
• [WIP] fix and tag [a] and [b]: brackets kept
• Keep literal braces in timeline message text #94/Exclude trailing punctuation from linkified URLs in the timeline #95: see {foo} here and text{.cls} stay literal. visit https://example.com. and (see https://example.com/a) still stop the link before the punctuation.
• Unchanged: bold, italic (*/_), strikethrough, inline code, [link](url), <autolink>, :smile: emoji, @mention, bullet/ordered/task lists, fenced code with highlighting, and tables
• Streaming: prefixes of a mixed message (bold, fence, table, text) parse correctly at each step, and an unclosed fence renders as code
• bun types and bun run ci pass

I did not check rendering in the desktop app.

Built in Ace

No. Made by a Claude Code subagent in a terminal at the maintainer's choice for this session; not an Ace capability gap. Dogfooding: #5.