…asis

Failing tests for Fixes #25180: a draft rebuilt from
Markdown and plain-text pastes (plain, inside inline code, with bold
markers inside a code span) must keep their text exactly.

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

Underscores after a word character or slash, as in /_handle_/ or
src/__test__.tsx, no longer open emphasis, so drafts rebuilt from Markdown
and plain-text pastes keep them. Pastes inside a code span stay literal, and
Tiptap's paste rules no longer restyle pasted code spans such as `**x**`.

Fixes #25180

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

…ltiline code span pastes

The `_` opening whitelist still rewrote words like `src/(_foo_).tsx`,
`~_user_/a`, `_build_/file.ts`, and `__init__.py`. Words with a slash or a
file extension now keep `_` literal, and ordinary `_emphasis_` uses the
original flanking rule. A multiline paste inside a code span now takes the
Markdown path, because a code span with a newline does not rebuild.

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

A backtick pasted into a code span was inserted literally, but the
single-backtick serializer cannot represent it, so the span rebuilt with
the pasted text parsed as Markdown. Such pastes now take the Markdown path,
like multiline pastes.

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

# Conflicts:
#	apps/web/src/composer-rich-text.ts

…eral

`_see src/a.ts_` now closes its italic span, and `__init__.py:42` stays
literal. Main now pastes single-line text into revealed code-span source
verbatim, so the separate code-span paste branch and its tests are dropped;
paste rules stay disabled because they still restyle pasted code spans.

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

Only underscores that pair up inside one URL, path, or filename word stay
literal, so `_read/write access_` and `_see src/a.ts_(optional)` style
again. Text dropped from another app takes the paste path, since paste
rules no longer style it.

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

`_see src/_a.ts_ now` paired the path's underscores with each other and
left the italic open. A run that ends a path word now stays a delimiter.

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