Cache connection config in the HTTP/1, HTTP/2 and HTTP/3 loop records

[williamthome]

Description

Finishes hoisting connection-stable config out of the per-request and per-stream hot paths into the connection loop records, so the steady state pattern-matches cached fields instead of re-reading proto_opts every time. Covers HTTP/1 (request/keep-alive timeouts, body buffering, hibernate_after, alt_svc), HTTP/2 (hibernate_after, alt_svc, request-slot counters), and HTTP/3 (request-slot counters); roadrunner_http:auto_headers/2 and the roadrunner_conn request-slot helpers now take the resolved values directly.

This is a consistency change, not a measurable throughput win: the reads it removes are O(1) map probes already in the preferred pattern-match idiom, so any delta sits inside bench variance.

• I have performed a self-review of my changes
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