Assistant replies flattened every <details> fold into always-visible text.
Split top-level folds out of each markdown segment in the thread feed and
render them as a native collapsible, closed unless the tag has `open`, as on
web. Pull request descriptions and other Markdown keep the flattening.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Fold boundaries, summaries and the open flag now come from real HTML tags,
so tags in comments, attribute values and code no longer split a reply.
Each segment carries the reference definitions it uses, an unclosed fold
runs to the end while a reply streams, and a fold body renders once instead
of being split again. Tapping a fold suspends end-of-feed scroll
maintenance like the feed's other disclosures.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

An open fold now closes at any `</details>` outside code, including one
inside a paragraph or list item, so the rest of the reply stays visible.
Any depth-0 `<details>` in a top-level HTML block starts a fold, which
splits compact sibling folds apart. Every segment carries all reference
definitions, rebuilt from the tree, so escaped labels, quoted definitions
and Unicode case folding resolve. Folds split before artifact templates,
so a template inside a fold renders in its body. A comment may sit
between `<details>` and `<summary>`.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

…itten

Copy each definition's source text instead of rebuilding it, so Windows
destinations keep their backslashes, and add only the definitions a
fragment mentions, after artifact templates are split out.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Definitions inside a compact HTML block are hidden from the raw parse but
exposed by flattening, and reference labels may wrap, so read definitions
from the flattened Markdown and match labels with collapsed whitespace.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Co-Authored-By: Claude Opus 5.5 <[email protected]>

# Conflicts:
#	apps/mobile/src/features/threads/ThreadFeed.tsx

Main now renders chat folds natively, but each fold body, the text around
it and the text between artifact cards render as separate Markdown
documents, so a [text][ref] whose definition sits in another fragment
showed as literal brackets. Drop this branch's own fold splitter and UI in
favour of main's, and keep the reference-definition fix: read the reply's
definitions once (after HTML flattening) and prepend to each fragment the
ones it mentions, copied as written.

AI-assisted; verified with the tests and tools listed above.

- Strip only the enclosing quotes' markers and indent from a wrapped
  definition, so a literal ">" in a label stays part of it.
- A fragment that defines a label keeps its own definition instead of
  getting another fragment's prepended ahead of it.
- Read definitions only when a reply splits into more than one fragment,
  so unsplit replies skip the extra parse on every streaming update.

AI-assisted; verified with the tests and tools listed above.

A label written as [ x ] did not match a fold's own [x] definition, so
the outside definition was prepended and took over the fold's link. Trim
labels and normalize bracket contents in the fragment the same way, as
CommonMark does, before the mention and self-definition checks.

AI-assisted; verified with the tests and tools listed above.