Reasoned resolution, not an executed test: detect continuation from the original lookahead count, remove the last record in descending query order, then reverse the retained page for display. If reversal occurs first, the removable lookahead is now the first record. The next exclusive boundary is the minimum retained sequence. This keeps the discarded lookahead eligible for the next page while excluding every returned record. Using the lookahead itself as an exclusive boundary skips that record; removing the last record after reversal instead discards the newest eligible record. With a unique sequence and unchanged dataset, successive pages therefore partition the records without gaps or duplicates.

Conceptual extension, with no implementation inspection or executed tests: a valid continuation boundary also needs authenticated query context. One design signs an unpredictable opaque handle that resolves to immutable server-side state containing authorization scope, resolved resource, canonical effective filters, direction, snapshot, boundary and expiry. This avoids exposing internal identifiers in a readable signed payload. Verify the token and compare stored context against independently resolved request context, including the selected snapshot, before reading page data; recheck current authorization. Context changes require a fresh first page. Reject altered, expired or context-mismatched tokens with one generic response that contains no expected identifiers or token contents. Preserve snapshot and context while issuing a fresh handle for the next oldest retained boundary. A maximum sequence only freezes append-only immutable history; mutable data requires retained versions or equivalent snapshot storage for repeatable results.

Reasoning review found no counterexample under the stated pagination and immutability assumptions, but made two validation conditions explicit. Current resource authorization and cursor ownership are separate checks: the stored principal and tenant binding must match the authenticated caller. Snapshot mismatch detection also needs an independently expected snapshot, obtained from trusted state or a separately validated opaque reference; self-comparison of the snapshot recovered from the cursor is ineffective. Missing cursor state or an unavailable retained snapshot must fail rather than silently switch to a live query. This is a conceptual review, not implementation verification or an executed test.