KubeStellar Console

# KubeStellar Console Development Rules

## Project Structure
- Frontend: React + TypeScript in `/web/`
- Backend: Go (Fiber v2) in root directory
- Build: `cd web && npm run build && npm run lint` before every commit
- Cards: Dashboard card components in `web/src/components/cards/`
- Hooks: Data fetching hooks in `web/src/hooks/`

## Card Development
- All data fetching MUST go through `useCache`/`useCached*` hooks
- Always destructure and pass `isDemoData` and `isRefreshing` to `useCardLoadingState()`
- Never use demo data during loading: `isDemoFallback && !isLoading`
- Hook ordering: `useCardLoadingState` AFTER hooks providing `isDemoData`

## Array Safety
- NEVER call `.join()`, `.map()`, `.filter()`, `.forEach()`, `for...of` on values that might be undefined
- Always guard: `(data || []).map(...)` or `(data || []).join(', ')`

## No Magic Numbers
- Numeric literals should be named constants, except trivial literals (`0`, `1`, `-1`) in clear local contexts
- Use constants from `lib/constants/` (time.ts, network.ts, ui.ts)

## Styling
- Tailwind CSS with `cn()` utility for merging classNames
- Never use raw hex colors — use semantic Tailwind classes (`text-foreground`, `bg-primary`, `bg-card`)
- Status colors: `text-green-400`/`bg-green-500/10` (success), `text-yellow-400`/`bg-yellow-500/10` (warning), `text-red-400`/`bg-red-500/10` (error), `text-cyan-400`/`bg-cyan-500/10` (info) — these map to the design system's semantic status tokens and are the only permitted palette classes

## Internationalization
- All user-facing strings use `t()` from `react-i18next`
- Keys in `web/src/locales/en/` JSON files
- Never use raw strings for UI text

## Go Backend
- Fiber v2 handlers: `func(c *fiber.Ctx) error`
- Use `fiber.NewError(statusCode, message)` for errors
- Always `make([]T, 0)` not `var x []T` (nil → null in JSON)
- Use `log/slog` for structured logging
- Multi-cluster queries use goroutines + sync.WaitGroup

## Cluster Deduplication
- Always use `DeduplicatedClusters()` when iterating clusters
- Multiple kubeconfig contexts can point to same physical cluster