ledger-history: symbolic resume for the scalar lanes

[wlmyng]

Description

Stacked on #27725. Deliberate wire-behavior change — sign-off required before merge.

Deletes the scalar lanes' eager-resume apparatus (the ScanCoordinate resume/stamp hooks and their u64 overrides, ~40 lines): every lane now carries an after Item as Excluded(coordinate), resolved at the store edge — checkpoints and transactions work like events. The four scalar-semantics unit tests flip back to their symbolic expectations; this commit and its parent document both worlds.

The change is confined to the after side — before bounds were already coordinate-exclusive in both worlds, and events are untouched. The three behaviors that change, for sign-off:

1. Exact-tie attribution: an after Item coinciding with a range edge keys strictly looser than the edge and loses terminal attribution (CURSOR_BOUND → CHECKPOINT_BOUND on ties).
2. Dense-collapse detection defers to the store edge: windows an after Item empties are no longer resolution-empty; at the tip their terminal reports LEDGER_TIP — the honest poll-again signal for tailing clients (the most common at-tip caller) — and scalar terminal stamps keep the raw coordinate instead of the eager edge.
3. Resume positions are equivalent throughout — no repeats, no skips; only the reason/cursor-byte reporting moves.

Complete wire delta (197-snapshot characterization suite, #27718; kv and fullnode byte-identical, 7 unique flips)

Snapshot	Change
checkpoints__after_at_window_end_asc	tie: CURSOR_BOUND → CHECKPOINT_BOUND, same cursor
checkpoints__after_bound_desc	desc terminal cursor boundary(cp=3) → boundary(cp=2) (raw stamp), reason unchanged
transactions__after_bound_desc	desc terminal cursor tx=3 → tx=2 (raw stamp), reason unchanged
checkpoints__after_item_last_asc	at-tip: CURSOR_BOUND → LEDGER_TIP, same cursor
transactions__after_item_last_asc	at-tip: CURSOR_BOUND → LEDGER_TIP, cursor cp=4 → cp=5 (tip-normalized)
walk__checkpoints__limit1_asc (final page)	same as checkpoints__after_item_last_asc
walk__transactions__limit1_asc (final page)	same as transactions__after_item_last_asc

All flips are on terminal no-item frames; no item rows change anywhere. Events and before-side snapshots: zero diffs.

Once #27718 lands, this PR gains the snapshot updates in-tree, making the delta CI-visible.

Test plan

The delta above is the test plan: enumerated via force-pass replay of the characterization suite; unit suites pass (172/125) with the restored symbolic expectations; clippy clean.

---

Release notes

Check each box that your changes affect. If none of the boxes relate to your changes, release notes aren't required.

For each box you select, include information after the relevant heading that describes the impact of your changes that a user might notice and any actions they must take to implement updates.

• gRPC: On ledger-history list endpoints, empty responses caused by an after cursor may report a different QueryEnd reason (CHECKPOINT_BOUND on exact range-edge ties; LEDGER_TIP when the cursor is at the ledger tip — poll again) and terminal cursors on such responses may carry the cursor's raw coordinate rather than its successor. Resume positions are unchanged: feeding any returned cursor back never repeats or skips items.
• Protocol:
• Nodes (Validators and Full nodes):
• JSON-RPC:
• GraphQL:
• CLI:
• Rust SDK:
• Indexing Framework:

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
sui-docs	Ready	Preview	Aug 17, 2026 7:33pm

2 Skipped Deployments

Project	Deployment	Actions	Updated (UTC)
multisig-toolkit	Ignored	Preview	Aug 17, 2026 7:33pm
sui-kiosk	Ignored	Preview	Aug 17, 2026 7:33pm