[UI] Refine Finance Category Badge Background Opacity

• Labels: good first issue, ui, difficulty:beginner, area:dashboard
• Target File: src/features/finance/components/transaction-list.tsx
• Estimated Time: 10–15 minutes
• Difficulty: Level 2 (Beginner)

Why This Matters

In the transactions ledger table, category tag badges should maintain optimal contrast against the Obsidian dark background (#050505) while preserving the subtle glassmorphism aesthetic.

Current Behavior

Category tags currently use bg-opacity-20, which can appear slightly washed out on lower-contrast monitors.

Requested Change

In src/features/finance/components/transaction-list.tsx, update the badge background utility classes to bg-opacity-15 border border-white/[0.08] for enhanced legibility and visual crispness.

Acceptance Criteria

• Badge opacity adjusted in src/features/finance/components/transaction-list.tsx.
• Visual contrast conforms to WCAG AA on dark backgrounds.
• npm run lint and npx tsc --noEmit pass with 0 errors.

Verification

npm run lint
npx tsc --noEmit

Contributor Notes

Scoped strictly to Tailwind CSS classes in a single component.

Open src/features/finance/components/transaction-list.tsx and locate the category tag badge classes. Update the background opacity and border utilities as specified, then run npm run lint and npx tsc --noEmit. Done means the badge uses the requested classes, meets the stated contrast requirement, and both checks pass.