AMS: purge-cli.js arg-parse error path bypasses the --json contract

[JSONbored]

Context

packages/loopover-miner/lib/purge-cli.js's runPurge (lines 168-170) handles the top-level arg-parse failure with console.error(parsed.error); return 2; instead of routing through the shared reportCliFailure/argsWantJson contract from cli-error.js that the rest of the CLI suite uses (see the related governor-pause-cli.js gap for the same bug class). The rest of runPurge's actual purge-result reporting is already correctly --json-aware — only this one parse-error path is affected.

loopover-miner purge --repo <bad-value> --json (or any other arg-parse failure) prints plain text to stderr instead of the documented {ok:false,error} JSON envelope, breaking script/automation consumers that always pass --json and expect a JSON response regardless of success/failure.

Requirements

• The arg-parse error path in runPurge must route through reportCliFailure(argsWantJson(args), parsed.error) instead of the raw console.error/return 2.
• Non---json behavior must be unchanged.

Deliverables

• Fix the single error path in runPurge (lines ~168-170) to use the shared contract.
• Add a regression test in test/unit/miner-purge-cli.test.ts covering the arg-parse error WITH --json (the existing test at lines 229-232 only covers the error without --json).

Test Coverage Requirements

99%+ Codecov patch target, branch-counted — both --json and non---json arms of the fixed path need direct tests.

Expected Outcome

loopover-miner purge --json on an arg-parse failure emits the standard {ok:false,error} JSON envelope, consistent with the rest of the module and the rest of the CLI suite.

Links & Resources

• packages/loopover-miner/lib/cli-error.js — the shared contract.
• Related: the same bug class in governor-pause-cli.js (filed separately, this is a narrower one-path instance).

[linear-code]

JSO-4044