Remove legacy 'haikulab' references from codebase

## Summary

Review the codebase for any remaining references to "haikulab" (a legacy project name) and safely remove them.

## Background

The project was previously named or associated with "haikulab". This legacy name may still appear in:
- Configuration files
- Environment variables
- Comments or documentation
- Package names or identifiers
- URLs or endpoints
- Database schemas or migrations

## Tasks

- [ ] Search codebase for all occurrences of "haikulab" (case-insensitive)
- [ ] Document where each reference is found
- [ ] Assess impact of removal for each occurrence
- [ ] Create migration plan if any references are in persistent storage (DB, S3, etc.)
- [ ] Remove/update references that are safe to change
- [ ] Test that removal doesn't break any functionality
- [ ] Update any external documentation if needed

## Acceptance Criteria

- No references to "haikulab" remain in the codebase (except historical git commits)
- All tests pass after removal
- No breaking changes to existing deployments

## Notes

Use `grep -ri haikulab` to find all occurrences.

Start with `grep -ri haikulab` from the repository root and document every match, grouping references by configuration, code, documentation, URLs, and persistent storage. Review each occurrence for deployment or migration impact before changing it. Done means no non-historical references remain, compatibility is preserved, and all tests pass.

Written by the indexing model from the issue text.