Function purgeScopedPaths

purgeScopedPaths(
    site: SitePhpDurableObject,
    paths: readonly string[],
    arm?: boolean,
    rowsPerPage?: number,
): {
    generation: number;
    policy: FanoutPolicy;
    purgedPages: number;
    reason: string;
    requeued: number;
}
Deletes exactly these pages and re-queues them, without touching the generation.

The generation already moved with the cachetags write; moving it again would leave the front worker one behind for its trust window.
Parameters
- site: SitePhpDurableObject
- paths: readonly string[]
- arm: boolean = true
- rowsPerPage: number = ROWS_PER_TAGGED_PAGE
Returns {
    generation: number;
    policy: FanoutPolicy;
    purgedPages: number;
    reason: string;
    requeued: number;
}
- Defined in src/do/invalidate.ts:99