Matrix outbound markdown was hitting the shared `resolveMarkdownTableMode`
"code" fallback for every send because the Matrix channel plugin never
declared `defaultMarkdownTableMode` in its `messaging` block at
`extensions/matrix/src/channel.ts:452`. Tables were emitted as
`<pre><code>` fenced blocks across every Matrix client.
This change declares `defaultMarkdownTableMode: "bullets"`, matching the
Signal and WhatsApp precedent at `extensions/signal/src/shared.ts:111`
and `extensions/whatsapp/src/shared.ts:261`. The choice matches the
cross-client compatibility profile the issue filer surveyed:
Element X iOS squashes HTML `<table>` and Element X Android drops cell
text entirely (element-hq/element-x-android#1551), while bullet lists
render cleanly across every Matrix client. Operators wanting the
previous fenced-code rendering can set `channels.matrix.markdown.tables:
"code"` explicitly; clients that do render real tables can opt in with
`channels.matrix.markdown.tables: "off"` (markdown-it's `table` rule is
already enabled by default through the markdown-it default preset, so
raw markdown tables flow through to native HTML tables on that path).
Docs and the changelog entry list Matrix alongside Signal and WhatsApp
as a bullet-default channel.
Fixes#78990.
docs/concepts/presence.md: replaced 8 curly quote and non-breaking
hyphen characters (U+201C/U+201D/U+2019/U+2011) with ASCII equivalents
so grep, copy-paste, and Mintlify search hit the right tokens.
Converted the 2-bullet Related list into a CardGroup adding cross-links
to gateway architecture and gateway protocol since presence is produced
by both surfaces.
docs/concepts/markdown-formatting.md: replaced 5 typography characters
(en-dash and curly quotes) with ASCII equivalents and converted the
2-bullet Related list into a CardGroup pointing at streaming/chunking
and system prompt.
docs/concepts/typing-indicators.md: replaced 4 typography characters
with ASCII equivalents and converted the 2-bullet Related list into a
CardGroup with the same Presence and Streaming cross-links.
Verified /concepts/streaming, /concepts/system-prompt,
/concepts/architecture, and /gateway/protocol targets all exist.
