Aggregate body errors[] messages in HttpError.from()

[freshlogic]

Summary

When a response body carries an `errors[]` envelope, `from()` now surfaces every `errors[].message` joined by `; ` as `err.message` instead of the default `"${status} ${statusText}"`.

This is the established convention for APIs that don't rely solely on HTTP status codes to signal failure:

• GraphQL servers (always 200 OK with `data.errors[]` — every Apollo/urql/graphql-request user hits this)
• REST APIs like FedEx Rate/Ship that return 200 + `errors[]` for application-level failures
• JSON:API responses, which use a top-level `errors[]` array

Aggregation runs regardless of HTTP status, so a 200-with-errors response and a 4xx-with-errors response both produce a fully populated `HttpError`. Codes and any other per-error fields stay accessible via `err.json.errors[]`.

Test plan

• Aggregates errors[] messages into err.message on 200 responses
• Aggregates errors[] messages on non-2xx responses too
• Leaves message as `"${status} ${statusText}"` when body has no errors[]
• All existing tests still pass

🤖 Generated with Claude Code

[coveralls]

Coverage Report for CI Build 25708010537

Coverage remained the same at 100.0%

Details

• Coverage remained the same as the base build.
• Patch coverage: 14 of 14 lines across 1 file are fully covered (100%).
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	48
Covered Lines:	48
Line Coverage:	100.0%
Relevant Branches:	13
Covered Branches:	13
Branch Coverage:	100.0%
Branches in Coverage %:	Yes
Coverage Strength:	4.83 hits per line

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💛 - Coveralls