Shared remote cache upload worker for spider and chromey.

This crate provides a high-performance, concurrent batch upload worker for sending cached HTTP responses to a remote hybrid_cache_server.

Client injection

Call [set_client] at startup to share your application's reqwest::Client — this avoids compiling a second TLS stack and reuses the existing connection pool. If never called, a minimal default client is created on first use.

Features

• Batch-drain: Collects pending jobs from the channel before uploading
• Concurrent uploads: Configurable parallelism via semaphore (default 8)
• Lock-free dedup: DashSet for in-flight key tracking (no Mutex, no deadlocks)
• Rate limiting: Per-spawn pacing without blocking the drain loop
• Batch POST: Uses /cache/index/batch when multiple jobs are ready
• Best-effort: try_enqueue never blocks; drops on full queue