feat(scraps): Markdown component

[natemoo-re]

Introduces a new <Markdown /> primitive that extends our existing marked pipeline with a declarative interface that supports static text and optionally enables animations with variant="streaming".

The goal is to replace the imperative sentry/utils/marked uses throughout the app with this new primitive and upgrade agentic interactions to support streaming.

See Deploy Preview

Basic Usage

<Markdown raw={"# Hello world!"} />

<Markdown
  raw={"# Replace headings with bold text\n\nParagraphs stay the same"}
  components={{
    Heading: ({ children => <strong>{children}</strong>
  }}
/>

<Markdown variant="streaming" raw={statefulText} />

markdown-stream.mov

[github-actions]

📊 Type Coverage Diff

Metric	Before	After	Delta
Coverage	93.51%	93.51%	±0%
Typed	135,324	135,556	🟢 +232
Untyped	9,393	9,406	🔴 +13

🔍 13 new type safety issues introduced

any-typed symbols (6 new)

File	Line	Detail
static/app/components/core/markdown/token.tsx	134	TableComp (var)
static/app/components/core/markdown/token.tsx	135	Thead (var)
static/app/components/core/markdown/token.tsx	136	Tbody (var)
static/app/components/core/markdown/token.tsx	137	Tr (var)
static/app/components/core/markdown/token.tsx	138	Th (var)
static/app/components/core/markdown/token.tsx	139	Td (var)

Type assertions (as) (7 new)

File	Line	Detail
static/app/components/core/markdown/markdown.tsx	59	as MarkedToken — token as MarkedToken
static/app/components/core/markdown/token.tsx	56	as MarkedToken — token as MarkedToken
static/app/components/core/markdown/token.tsx	80	`as 1
static/app/components/core/markdown/useStreamingAnimation.ts	158	as Element — parent as Element
static/app/components/core/markdown/useStreamingAnimation.ts	257	as number — id as number
static/app/components/core/markdown/useStreamingAnimation.ts	268	as HTMLElement — element as HTMLElement
static/app/components/core/markdown/useStreamingAnimation.ts	278	as Text — node as Text

This is informational only and does not block the PR.