feat(ca/acme/eab): add --json output to add, list, and remove

[joshdrake]

Summary

Adds a --json flag for machine-readable output across the entire step ca acme eab command chain (add, list, remove). Previously these subcommands only emitted fixed-width column text, making them awkward to script against — add.go even carried a standing // TODO(hs): JSON output, so that executing this command can be more easily automated?.

What changed (command/ca/acme/eab/)

• eab.go — Exported cliEAK's fields with JSON tags (id, provisioner, reference, plus omitempty key/createdAt/boundAt/account). Guarded createdAt with an IsZero() check mirroring the existing boundAt handling so unset timestamps drop out via omitempty. Added a shared package-local jsonFlag.
• add.go — --json marshals the created key including the secret (the whole point of add) as a JSON object; replaced the TODO(hs).
• list.go — --json collects every page into a JSON array and bypasses the $PAGER machinery. The secret HMAC key is omitted, matching the table's existing ***** masking; an empty result is [].
• remove.go — --json emits {"provisioner":…,"id":…,"deleted":true} on success.
• eab_test.go — New; the package's first tests, covering toCLI (including zero-timestamp handling) and the JSON contract for both the add and list shapes.

Example output

// add --json
{
  "id": "zFGdKC1sHmNf3Wsx3OujY808chxwEdmr",
  "provisioner": "my_acme",
  "reference": "my_ref",
  "key": "Zm9vYmFyYmF6..."
}

// list --json  (key omitted, matching the masked table)
[
  {
    "id": "zFGdKC1sHmNf3Wsx3OujY808chxwEdmr",
    "provisioner": "my_acme",
    "createdAt": "2026-07-06 12:00:00 +00:00",
    "reference": "my_ref"
  }
]

// remove --json
{
  "provisioner": "my_acme",
  "id": "zFGdKC1sHmNf3Wsx3OujY808chxwEdmr",
  "deleted": true
}

Design decisions

• list --json omits the key rather than exposing every secret in bulk — this preserves today's posture where only add (at creation time) ever reveals a key.
• All three subcommands get the flag for a consistent chain.

Testing

• go build ./..., gofmt, and go vet clean.
• golangci-lint with the smallstep config → 0 issues.
• New unit tests pass; --json verified present in --help for all three subcommands.
• Not exercised against a live Certificate Manager CA (requires admin credentials); the JSON shape is covered by the unit tests instead.

🤖 Generated with Claude Code

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