chore(deps): update dependency streamdown to v2.5.0

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
streamdown (source)	2.4.0 → 2.5.0

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Release Notes

vercel/streamdown (streamdown)

v2.5.0

Compare Source

Minor Changes

• d6666b6: Add lineNumbers prop to disable line numbers in code blocks
• d4ec6c0: Add meta prop to CustomRendererProps. Custom renderers now receive the raw metastring from the code fence (everything after the language identifier, e.g. ```rust {1} title="foo" → meta = '{1} title="foo"'). The prop is optional (meta?: string) and is undefined when no metastring is present. Existing custom renderers are unaffected.

Patch Changes

• ac8d839: Add staggered animation-delay to streaming word/character animations so new content cascades in sequentially instead of all animating simultaneously. Configurable via the new stagger option (default 40ms). Set stagger: 0 to restore the previous behavior.

• add5374: Enable horizontal scrolling on code blocks so long lines are accessible instead of being clipped by overflow-hidden.

• 75845c0: Fix unnecessary re-renders of code blocks during streaming updates.

  Problem: In streaming mode, when new content arrives (e.g. a paragraph is appended), completed code blocks that haven't changed were still re-rendering. This happened because the Streamdown component used inline object literals as default parameter values for linkSafety ({ enabled: true }). Every time children changed and Streamdown re-rendered, these inline defaults created new references, which caused the contextValue useMemo to recompute a new StreamdownContext object. Since React propagates context changes through memo boundaries, any context consumer inside a memoized Block (such as CodeBlock) would re-render even though the block's own props were unchanged.

  Fix: Extract the inline default values for linkSafety into module-level constants (defaultLinkSafetyConfig). This ensures referential stability across renders, so contextValue only recomputes when the actual values change — not just because children updated.

• 8b1c262: fix: prepend UTF-8 BOM to CSV downloads for Excel compatibility

  • save() now prepends \uFEFF for text/csv string content so Excel on
    Windows detects UTF-8 encoding instead of falling back to ANSI.
  • TableDownloadButton refactored to use save() instead of inline Blob
    creation, ensuring the public API also gets the BOM fix.

• b105c64: Fix custom tag content being prematurely split when content follows the opening tag on the same line and contains double newlines (\n\n). The preprocessor now ensures proper HTML block structure so the parser treats the entire tag as a single unit.

• 9e6f991: Increase dropdown z-index for table copy and download menus to prevent clipping by surrounding elements.

• 9c18748: docs: document required CSS custom properties (shadcn/ui design tokens) in README

• 7b62e9a: Replace Tailwind v4-only *:last: and *:first: variant syntax with [&>*:last-child]: and [&>*:first-child]: arbitrary variants for compatibility with both Tailwind CSS v3 and v4. Fixes caret rendering on every line instead of only the last child in v3.

• Updated dependencies [e50b0c4]

• Updated dependencies [716a5f0]

  • remend@​1.3.0

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