fix(dashboard): explicit @source for Tailwind v4 (fixes #179)

[AsimRaza10]

Summary

Fixes #179 — dashboard renders unstyled when the plugin is installed in a gitignored directory (which is the default marketplace install path: ~/.claude/plugins/cache/..., ignored by ~/.claude/.gitignore).

Root cause

Tailwind v4 source detection walks the nearest .git via git ls-files. When the dashboard sources are inside a gitignored subtree of an ancestor repo, detection returns 0 files and the Oxide engine skips all utility generation — so the dashboard ships with @theme / @layer base only, and every element collapses to default block flow.

Fix

Add explicit @source directives in packages/dashboard/src/index.css. Per the Tailwind v4 docs, this is the supported escape hatch and is a no-op when automatic detection already works.

@import "tailwindcss";
@source "./**/*.{ts,tsx,js,jsx,html}";
@source "../index.html";

Verification

• Production CSS bundle: ~9 KB → 55.68 KB
• Utility selectors confirmed present in the built bundle: .flex, .grid, .absolute, .w-full, .h-full
• pnpm --filter @understand-anything/dashboard build succeeds
• No effect on installs where source detection already works

Test plan

• pnpm install
• pnpm --filter @understand-anything/dashboard build succeeds
• Install plugin via the marketplace into the default cache path, run /understand then /understand-dashboard, and confirm the dashboard renders styled