refactor: Unify CLI request and error handling
Summary
Use one private request transport beneath existing GET/POST interfaces; preserve query, headers, bodies and HTTP/application error behavior.
Verification
94 tests in 14 files and production build pass. Independent reviewer repeated 17 client tests and found no actionable issues.
Scope and review
Part of the user-requested Recoup monorepo untangle-codebase workflow. Audit and decision log preceded implementation. Changes stay in this owning repository; no production deployment or main-branch merge requested. No broad comment/test-pruning sweep. Existing local work and retired checkouts preserved.
Each repository PR is independently reviewable; the Mono report will collect the coordinated audit, retained cases and check limitations.
Summary by cubic
Unifies get and post behind a single private request helper so query building, headers, body handling, and error policy live in one place. No behavior change for callers: GET and POST responses keep the existing error precedence (data.error, then data.message, then Request failed: <status>), and malformed JSON now propagates without retrying.
- Adds tests covering GET and POST response contracts, including application-level errors and invalid JSON responses.