[saminsohag]

Summary

Upgrades mobile's gpt_markdown from 1.2.1 to 1.3.4 and moves off the APIs that 1.3 deprecates, so mobile renders through the package's default parser instead of the legacy regex pipeline.

Depends on #7545. This branch is stacked on its commit (2f19e124). Review only the commit after it; I'll rebase onto main once #7545 merges.

API migration

• @mention, #channel and custom emoji move from InlineMd + inlineComponents to InlinePattern + inlinePatterns (InlinePattern.prefixed for @/#). Passing inlineComponents forced the whole widget onto the legacy parser.
• InlinePattern's default scopes already exclude link labels, so the explicit allScopesExceptLinkLabel overrides from fix(mobile): keep token labels visible in authored Markdown links #7545 are no longer needed; the [#channel](url) / [@mention](url) / [:emoji:](url) regression tests still pass.
• linkBuilder → inlineLinkBuilder. Ordinary links are now LinkTextSpans (they wrap across lines, sit on the baseline and are selectable); Buzz permalink chips and audio attachments stay widgets via asWidgetSpan. Tap handling moved into _openLink, unchanged in behavior.

Autolinking

Buzz's own normalizeBareLinks pre-processor is removed in favor of gpt_markdown's autolink with autolinkSchemes: {'buzz'}, as the package docs recommend. Visible differences:

• Trailing punctuation now stays outside HTTP(S) links too (GFM rules), not only Buzz links.
• www. hosts and email addresses become links.
• A bare buzz:// URL of an unknown shape becomes an ordinary link (it does nothing when tapped), not a chip.

Fixes the new rendering exposed

• Stray backtick in links. The mention rewrite in MessageContent re-added backticks around every odd segment, which adds one extra backtick when the count is odd (e.g. a 4-backtick fence closer). Previously hidden; with autolink the link swallowed it.
• Screen readers. A Buzz link chip's placeholder merged its whole paragraph — mention and channel pills included — into a single semantics node with one label and one tap. Each chip now gets its own node, so every pill is its own stop with its own action. Repo/PR/issue chips no longer advertise a tap they cannot perform.
• Height-bounded previews. The forum post card and the pulse reply preview squeezed MessageContent into a max height; the new block layout reported a RenderFlex overflow. They now lay the content out at its natural height and clip it.

Related issue

Closes #8179.

Related:

• fix(mobile): keep token labels visible in authored Markdown links #7545, which this builds on.

Testing

• just mobile-check — format and analyze clean, no deprecation warnings.
• just mobile-test — 3041 passed, 0 failed.
• just file-size-check — passes.
• New message_content_autolink_test.dart ports the deleted normalizer's cases (code-span boundaries, delimiters, punctuation, entity permalinks) to assertions on what MessageContent actually renders.
• New gives each inline pill its own screen-reader stop test; verified it fails without the semantics fix.
• Link tests now find and tap links through the span tree (LinkTextSpan) instead of Text widgets.

[github-actions]

🔐 Codex Security Review

Status: review required for the current range.

The current range is 5a93e862ee28b8804f681ae15997a00bdc45d1bf...22657935126cd101280febe557209a2ce9b65844.
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