Response envelopes omit Cursor and Location from PrintMembers (V27)

[Blind-Striker]

Source: multi-agent review of PR #26, adversarial verification (CONFIRMED, severity 1, shipped-runtime diagnostics). 2026-08-14. Scope widened by the 2026-08-17 comment below.

The generated guarded PrintMembers override on response envelopes prints the shared metadata and the payload, but not the other envelope-owned members:

• Cursor on cursor-list envelopes. Logging a successful page loses the continuation token that identifies it. Example: src/OpenCode.Sdk/Sessions/SessionListResponse.cs prints Sessions but not _cursor.
• Location on envelopes with a server-resolved location. Example: src/OpenCode.Sdk/Agents/AgentListResponse.cs.

Status 2026-09-27: still true at v2.0.18. Two cursor envelopes and 41 Location envelopes are affected.

Fix: in EnvelopeEmitter, make PrintMembers append every envelope-owned diagnostic member in a fixed order: payload, cursor when present, location when present. Read backing fields, not guarded public getters, so the error path stays safe. Regenerate, re-approve snapshots, and pin it with a contract assertion on ToString() output.

Trigger: the next change that touches the envelope emitters.

[Blind-Striker]

The same PrintMembers mechanism also drops the resolved location sibling.

EnvelopeEmitter emits Location, but its custom PrintMembers override appends only the payload. Calling ToString() on a successful selected Shell location envelope therefore omits the server-resolved location, just as this issue's existing cursor finding omits the cursor.

Broaden the fix so PrintMembers appends every envelope-owned diagnostic member in deterministic order: payload, cursor when present, and location when present. Keep the error path safe by reading backing fields instead of guarded public getters.

Trigger: execute with this issue's existing cursor fix; current selected Shell operations already expose the location omission.

[Blind-Striker]

Status 2026-09-14: still true on 0.8.0-preview.2 — the guarded PrintMembers override on cursor-list envelopes (for example SessionListResponse) prints the payload but not Cursor, so logging a successful page loses the continuation token. Small generator fix in the envelope emitter plus a snapshot re-approval; tracked on the project board.