Add JSON output for utility list commands

[bolasse1234]

Closes #146. Related to #133.

This covers the utility-side list commands that still only had the human-readable output path.

What changed:

• added --json to sh1pt iterate agents list
• added --json to generated adapter category list commands such as sh1pt bots list
• added --json to sh1pt secret list; it returns key metadata only and never secret values
• added a focused regression test that checks these command surfaces keep the JSON option

Verified:

• corepack pnpm --filter @profullstack/sh1pt typecheck
• corepack pnpm vitest run packages/cli/src/commands/utility-json-output.test.ts
• corepack pnpm --filter @profullstack/sh1pt-core --filter @profullstack/sh1pt-policy --filter @profullstack/sh1pt build
• smoke-tested:
  • corepack pnpm exec tsx packages/cli/src/index.ts iterate agents list --json
  • corepack pnpm exec tsx packages/cli/src/index.ts bots list --json
  • corepack pnpm exec tsx packages/cli/src/index.ts secret list --local --json

I kept this separate from the primary-verb JSON PR so the changes are easy to review independently.