Method mutate

src/node/services/memoryMeta.ts:151–163

* Read-modify-write cycle under the sidecar mutex. Persists before updating * the in-memory cache so observers never see state that didn't make it to * disk. Entries that end up entirely default are dropped.

(update: (entries: Record<string, MemoryMetaEntry>) => void)

   * disk. Entries that end up entirely default are dropped.
   */
  private async mutate(update: (entries: Record<string, MemoryMetaEntry>) => void): Promise<void> {
    await this.lock.withLock("meta", async () => {
      const meta = await this.load();
      const entries = { ...meta.entries };
      update(entries);
      for (const [key, entry] of Object.entries(entries)) {
        if (isEmptyEntry(entry)) delete entries[key];
      }
      const next: MemoryMetaFile = { entries };
      await writeFileAtomic(this.metaPath, JSON.stringify(next, null, 2), { encoding: "utf-8" });
      this.cache = next;
    });
  }

  /** Logical keys of all pinned memory files. */
  async getPinnedKeys(): Promise<Set<string>> {