# Wave B-5b: `@suaveplan/game-server` performance slice

**Package**: `@suaveplan/game-server`
**Status**: PROPOSED
**Type**: feature-add (additive to existing 0.1.0 package)

## Why

Wave A landed the `@suaveplan/game-server` core foundation. Five
parallel waves now extend the package along orthogonal axes; B-5 owns
the **matchmaking + performance** axis. This change covers the
performance half; a sibling change (`game-server-matchmaking`) covers
queue / matcher / spectator / engine.

The upstream reference
(`/mnt/s/web/suaveplan/packages/universal/game-server/src/performance/`)
ships three modules — `ObjectPool`, `SessionPool`, `NetworkTierAdapter`
— but couples them to upstream-only types (`Logger`,
`GameEventEmitter`, `SessionNodeImpl`) and lacks typed-error /
Zod-validated boundaries. This slice ports the algorithms, replaces the
upstream couplings with `@suaveplan/types` (`Clock`) plus typed
observer callbacks, and adds OTel-native instrumentation across all
three modules.

## What changes

- ADDED: `src/performance/object-pool/` — generic typed object pool
  with factory + reset + optional dispose; configurable
  `initialSize`/`maxSize`/`preAllocate`; `acquire` / `release` /
  `withObject` / `clear` / `dispose` / `getStats`; two OTel counters;
  typed-error boundary (`POOL_EXHAUSTED`, `POOL_DISPOSED`,
  `RELEASE_FOREIGN_OBJECT`, `INVALID_POOL_CONFIG`).
- ADDED: `src/performance/session-pool/` — session-specific wrapper
  over `ObjectPool` that pools plain-data `PooledSession` records
  (`id`, `type`, `metadata`, `children[]`); injectable `Clock`;
  `acquireSession`/`releaseSession`/`withSession`/`getStats`.
- ADDED: `src/performance/network-tier-adapter/` — bridge between the
  game-server's matchmaking layer and the `@suaveplan/network` tier
  model; `registerNodeCapabilities` / `getOptimalTier` /
  `getLoadBalancingRecommendations` / `validateTierCapacity` /
  `getStats`; one OTel counter; typed-error boundary
  (`INVALID_TIER_CONFIG`, `UNKNOWN_TIER`); optional
  `onCapabilityUpdated` listener.

## Impact

- Affected specs: `openspec/specs/game-server/spec.md` (game-server
  capability).
- New error codes: `POOL_EXHAUSTED`, `POOL_DISPOSED`,
  `RELEASE_FOREIGN_OBJECT`, `INVALID_POOL_CONFIG`,
  `INVALID_TIER_CONFIG`, `UNKNOWN_TIER`.
- New subpath exports: `./performance/{object-pool, session-pool,
  network-tier-adapter}`.
- No `core/` / `state/` / `engine/` / `network/` modifications.