feat(daemon): add server-side sorting for ListRuns and ListIssues

[proboscis]

Summary

• Add sort_by and sort_order parameters to ListRunsRequest and ListIssuesRequest in the protobuf API
• Implement server-side sorting in the daemon's proto handler for both runs and issues
• Regenerate Go and Python protobuf code

Issue Reference

Closes orch-385

Changes

Proto Changes (api/orch.proto)

• Added SortOrder enum with SORT_ORDER_UNSPECIFIED, SORT_ORDER_ASC, SORT_ORDER_DESC
• Added sort_by and sort_order fields to ListRunsRequest
• Added sort_by and sort_order fields to ListIssuesRequest

Handler Changes (internal/daemon/proto_handler.go)

• Added sortRuns() function supporting sort by: updated_at (default), started_at, issue_id, status
• Added sortIssues() function supporting sort by: modified_at (default), id, title, status
• Updated handleProtoListRuns() to call sortRuns() with request parameters
• Updated handleProtoListIssues() to call sortIssues() with request parameters (replaces hardcoded ModifiedAt sort)

Verification

Build passes

$ go build ./...
# no errors

All daemon tests pass

$ go test -v ./internal/daemon/...
...
=== RUN   TestListRunsAPI
=== RUN   TestListRunsAPI/list_all_runs
=== RUN   TestListRunsAPI/filter_by_issue_id
=== RUN   TestListRunsAPI/filter_by_status
=== RUN   TestListRunsAPI/pagination
=== RUN   TestListRunsAPI/run_summary_has_URI
--- PASS: TestListRunsAPI (0.04s)
...
=== RUN   TestListIssuesAPI
=== RUN   TestListIssuesAPI/list_all_issues
=== RUN   TestListIssuesAPI/filter_by_status
=== RUN   TestListIssuesAPI/pagination
=== RUN   TestListIssuesAPI/issue_summary_has_URI
--- PASS: TestListIssuesAPI (0.04s)
...
PASS
ok      github.com/s22625/orch/internal/daemon  1.857s

Behavior

• Default sort order is descending (SORT_ORDER_DESC) when unspecified
• Default sort field is updated_at for runs and modified_at for issues
• Clients can now request specific sorting from the daemon instead of sorting client-side