Fix stale loadEnv import in ship/skim, update help text and CLAUDE.md
- Replace dead `loadEnv` import (from deleted env.js) with `loadConfig` from config.js in ship.js and skim.js, matching the pattern already used by firehose.js
- Update --did option help text to reflect config-based DID resolution
- Add Verification section to CLAUDE.md with pre-commit testing notes