Add async-std file I/O and directory traversal in store.rs:
- find_nbd_root / find_nbd_root_from: walk up from cwd to locate .nbd/
- tickets_dir, ticket_path: pure path helpers
- ensure_tickets_dir: create .nbd/tickets/ on first use
- write_ticket / read_ticket: JSON serialisation round-trip
- list_tickets: read all *.json files, sort by priority descending
Add 8 unit tests covering write/read round-trip, missing-ticket
error, priority-sorted list, empty directory, grandparent traversal,
traversal failure, and path helpers.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Define Status and TicketType enums with serde snake_case/lowercase
serialization, Ticket struct with all fields, Ticket::new constructor,
validate_priority, and generate_id using RandomState entropy. Add 9
unit tests covering roundtrips, enum serialization, priority validation,
and ID format/uniqueness.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Elijah Voigt