Fix featured emphasis and mobile nav closing; upgrade Astryx 0.5.2

[walishcs]

Changes

• Render featured publication venue emphasis using the existing single-asterisk parser, preserving escapes and other card metadata.
• Retain the completed mobile fade while Astryx finishes the native dialog close; prevent the second slide-out animation and respect reduced motion.
• Pin core, CLI, and four themes to Astryx 0.5.2; official upgrade requires no codemods.

Verification

• Clean lockfile install, Astro check, 51 tests, formatting, production build, and Astryx doctor passed.
• Browser verified computed italic style, full fade opacity/transform sampling, reopen, Escape, focus restoration, and link navigation.
• Production output has italic markup and excludes old and Keystatic routes.
• npm audit endpoint timed out; no audit fix or unrelated dependency changes included.

Feature-only cherry-picks from template; editor-owned content is unchanged.