augment OutboundHTTPResponse with helpful fields for metrics

[jinhoonbang]

• augment OutboundHTTPResponse with IsExternalEndpointError and ExternalEndpointLatency
• add CacheAgeLimit to cresettings

[github-actions]

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[github-actions]

apidiff results - no incompatible changes detected ✅

Module: github-com-smartcontractkit-chainlink-common

Status: ✅ 2 compatible changes

(Full summary: https://github.com/smartcontractkit/chainlink-common/actions/runs/17477042499/#summary-49639335355)

[Copilot]

Pull Request Overview

This PR augments the OutboundHTTPResponse struct with additional fields to support better metrics collection and adds cache age limit configuration to HTTP action settings.

• Added error classification and latency tracking fields to OutboundHTTPResponse
• Introduced CacheAgeLimit configuration setting for HTTP actions
• Updated default configuration files to include the new cache age limit setting

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
pkg/types/gateway/action.go	Added IsExternalEndpointError flag and ExternalEndpointLatency field to OutboundHTTPResponse struct
pkg/settings/cresettings/settings.go	Added CacheAgeLimit setting to httpAction struct and default configuration
pkg/settings/cresettings/defaults.toml	Added CacheAgeLimit default value in TOML format
pkg/settings/cresettings/defaults.json	Added CacheAgeLimit default value in JSON format

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