perry-ext-http's AGENT_CLIENTS cache never evicts #10328

Problem

perry-ext-http's AGENT_CLIENTS cache never evicts. It holds one reqwest::Client per http.Agent, retained for the entire life of the process. The comment in the code itself acknowledges this.

Why it matters

A long-running program that creates many distinct http.Agent instances over its lifetime (which Node programs commonly do, including per-request or per-tenant agents in some frameworks) accumulates one reqwest::Client's worth of connections, buffers and TLS state per agent, unbounded, for as long as the process runs.

What would fix it

An eviction policy on AGENT_CLIENTS — LRU with a cap, a TTL, or tying an entry's lifetime to the Agent object's own GC lifetime — so the cache does not grow without bound over a long-running process.