feat(docusaurus): refresh typography, category colors, and card hover states

[jimmieego]

Fixes N/A

Summary

Changes

Visual refresh of the documentation site, scoped to typography, category color coding, and server card hover interactions. No content or routing changes.

• Add src/categoryMeta.ts as a single source of truth mapping each of the 10 server categories to an accent color and a Feather icon. All colors clear 4.5:1 contrast on white. ServerCards consumes it instead of its previous inline icon maps.
• Color-code the server catalog cards by category: tinted icon chip, colored category label, and a category-colored top hairline revealed on hover, with a subtle lift and shadow. Honors prefers-reduced-motion.
• Support ?category= and ?workflow= URL params on the catalog so links can open a pre-filtered view, and add a "Clear filters" button.
• Introduce brand typography (Public Sans for UI text, IBM Plex Mono for code, loaded via Google Fonts with preconnect) and design tokens in custom.css: Squid Ink headings, Cloudscape action blue as the Infima primary, a neutral ink ramp, and a Smile Orange footer rule.
• Restyle the re:Invent callout on the intro page to match the new palette.

User experience

Before: all server cards look identical regardless of category (single blue accent, plain text category tag), system default fonts, and no way to link to a filtered catalog view.

After: each category has a consistent accent color across icon, label, and hover treatment, making the catalog easier to scan; headings and body text use AWS brand typography; catalog views are deep-linkable via URL params. Verified with npm run build (both en and ja locales pass link checking; the one broken-anchor warning on healthimaging-mcp-server#installation is pre-existing).

Screenshots

Server catalog (/servers):

Before	After

Card hover state (first card hovered — after adds a lift, shadow, and category-colored top hairline):

Before	After

Intro page typography (Public Sans body/headings, Squid Ink heading color):

Before	After

Checklist

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• I have reviewed the contributing guidelines
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented

Is this a breaking change? (Y/N) N

RFC issue number: N/A

Checklist:

• Migration process documented
• Implement warnings (if it can live side by side)

Acknowledgment

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