## Why

The existing `@suaveplan/day-night` package uses hardcoded sinusoidal sun arcs, 30-day moon cycles, and preset lighting tables. It is not physically derived, not extensible to other planets, and conflates game-clock concerns with rendering concerns. This change introduces two gaming-layer packages that consume the astronomical core from `@suaveplan/universe` to provide a configurable game clock and physically-derived environment lighting.

## What Changes

- **Retire `@suaveplan/day-night`** — replaced by `@suaveplan/gaming-universe` (game clock + events) and `@suaveplan/gaming-environment-lighting` (sky colour + gameplay modifiers).
- **Create `@suaveplan/gaming-universe`** — wraps `UniverseClient` with configurable N× game clock via `@suaveplan/timing`'s `AsyncScheduler`, emitting season/sunrise/eclipse events through `@suaveplan/events`.
- **Create `@suaveplan/gaming-environment-lighting`** — replaces hardcoded day-night presets with Rayleigh/Mie scattering sky colour, twilight star visibility thresholds, multi-satellite moonlight, and continuous gameplay modifiers derived from ambient light.

**BREAKING**: `@suaveplan/day-night` is retired — consumers must migrate to `@suaveplan/gaming-universe` + `@suaveplan/gaming-environment-lighting`.

## Capabilities

### New Capabilities

- `gaming-universe`: Game-clock astronomical wrapper — N× time scale, event emission, and scene queries at game time.
- `gaming-environment-lighting`: Physically-derived environment lighting — sky colour, star visibility, moonlight, and gameplay modifiers.

### Modified Capabilities

- `gaming-day-night`: **Retired** — all requirements absorbed by `gaming-universe` and `gaming-environment-lighting`. No spec delta; capability removed on archive.

## Impact

- **New packages**: 2 packages in `universal/gaming`.
- **Dependency graph**: `universe` → `gaming-universe` → `gaming-environment-lighting`.
- **Prerequisite**: `@suaveplan/universe` and its downstream providers (`solar-system`, `stars`, `tides`) must be implemented first.
- **Downstream consumers**: Any package depending on `@suaveplan/day-night` must migrate.
- **Deferred integrations**: R3F / Three.js rendering integration, multiplayer game time sync, `@suaveplan/weather` integration are explicitly out of scope.