# OpenSpec Change: network-plugin-content-delivery-store

- **Change ID**: network-plugin-content-delivery-store
- **Package**: `@suaveplan/network-plugin-content-delivery` (extension)
- **Status**: PROPOSED
- **Type**: extension
- **Date**: 2026-05-05

## Why

The core `network-plugin-content-delivery` change (commit landing 2026-05-05) ships `ChunkIndex`, `ChunkRequestRouter`, `RedundancyManager`, `IntegrityVerifier`, and the `ContentDeliveryPlugin` facade — the mesh-CDN primitives that don't require external integrations. The `ChunkStore` subsystem was deferred per the parent proposal's `## Deferred to follow-up changes` block because it requires deep coupling to `@suaveplan/drive` (browser OPFS/IndexedDB, Node filesystem) and an LRU eviction policy that warrants its own design + test surface.

This change adds `ChunkStore` to the existing package without breaking the core surface.

## What changes

- **ADDED**: `ChunkStore` interface over `@suaveplan/drive` for persisting chunks. Browser path uses OPFS/IndexedDB via the existing drive adapter; Node path uses the filesystem driver.
- **ADDED**: TTL-based eviction with LRU ordering — chunks evicted oldest-first when the store exceeds `maxBytes` or when the chunk's age exceeds `maxAgeMs`.
- **ADDED**: `ChunkStoreEvent` bus topic (`cd:chunk-stored`, `cd:chunk-evicted`) so `ChunkIndex` can react to local state without polling.
- **ADDED**: `ContentDeliveryPlugin.store` getter wires the new subsystem onto the plugin facade.
- **ADDED**: `NETWORK_CD_CODES.STORE_QUOTA_EXCEEDED` if the new code is needed for backpressure (decision deferred until implementation).

## Verification approach

- `src/store/chunk-store.spec-conformance.test.ts` — pins put/get round-trip, TTL expiry, LRU eviction, byte-budget enforcement.
- `src/store/chunk-store.eviction.spec-conformance.test.ts` — pins eviction order under mixed insert / read traffic.

## Migration impact

None — additive only. Existing consumers of `ContentDeliveryPlugin` see one new optional config field (`store?: ChunkStoreConfig`).