- Added tests for extractIssuePrefix, loadIssuesFromJSONL, detectPrefix, writeIssuesToJSONL
- Added tests for walkWithDepth depth limiting and hidden directory skipping
- Added tests for DiscoverDaemons registry and legacy discovery paths
- Improved test coverage for cmd/bd and internal/daemon
- Created global daemon registry at ~/.beads/registry.json
- Daemons auto-register on start, unregister on graceful shutdown
- DiscoverDaemons() now uses registry instead of filesystem scan
- Instant daemon discovery (35ms vs indefinite hang)
- Auto-cleanup of stale registry entries
- Full test coverage
Closes bd-07b8c8, bd-acb971c7