fix(textUtils): Emit Auto-link target/rel via Mdast

[Xavier-Charles]

Problem

The remarkRegex plugin in textUtils.tsx attaches hProperties to the
link node's value field. mdast-util-to-hast (used by react-markdown) only
reads hProperties from a node's data field, so the properties were
silently dropped — every auto-linked URL lost its target="_blank" and
rel="noopener noreferrer" attributes.

This is both:

• a security/UX regression — generated links no longer open in a new tab
  and lost the noopener protection, and
• the cause of the failing remarkRegex() snapshot test.

The attributes were placed under value only to satisfy the
IParentWithLiteral interface (which required a value), so the type shape
was masking the real bug.

Fix

• Move hProperties from value → data (the correct mdast field).
• Relax IParentWithLiteral so link nodes aren't forced to carry value.
• Remove the obsolete duplicate snapshot entry.

Verification

Check	Result
textUtils.test.ts	✅ 4/4 pass (was failing)
Typecheck (frontend + ui-kit)	✅ clean
Lint (changed file)	✅ clean
Full unit suite	12 failed → was 13 (this fix), no regressions

The remaining 12 failures are pre-existing environmental issues (Web Share
API, ResizeObserver, redux store, firebase script loading) unrelated to this
change.