getVerbsWithPagination was offset-only: it re-scanned from shard 0 on every page
and early-terminated at offset+limit, so a full edge walk was O(N²) (a consumer
measured ~19k edges → 27s paging at 900/page). It now accepts an opaque resume
token (cv1:<shard>:<verbId>) that resumes the shard walk immediately AFTER the
last returned verb — O(N) total at any page size, no scale cliff.
- Stable within-shard order (sort by verb id); ids come from the path so verbs
skipped by the cursor are never read.
- Cursor supersedes offset when present; offset path preserved for back-compat,
and offset callers now get a usable nextCursor so they can switch to cursor
paging. Foreign/malformed tokens decode to null → offset fallback (no throw).
- The relationships stream generator now uses cursor (was offset → O(N²)).
- Parity with the noun side (getNounsWithPagination already cursored).
Test: tests/unit/storage/verb-cursor-pagination.test.ts — a full cursored walk
visits every edge exactly once (no dup, no skip), matches the offset walk's set,
and a foreign cursor falls back gracefully.
