OpenChamber transcript hides new messages in sessions created before 1.18.16

Description

Environment: opencode 1.18.16 (upgraded from 1.18.15), OpenChamber 1.18.3 web UI (Home Assistant add-on).

Symptom: In sessions that existed before the 1.18.16 upgrade, new messages no longer appear at the end of the transcript. The transcript appears to end at the last pre-upgrade message; new questions/answers are effectively invisible. Sessions created after the upgrade work fine.

Data is intact — GET /session/{id}/message returns every message including the newest, so this is a client-side ordering problem, not data loss.

Root cause (confirmed against real data): opencode's message-ID generation changed in 1.18.16. Through 1.18.15 IDs were a monotonic sequence (msg_f7… → msg_ff…) so string order equalled chronological order. Starting 1.18.16 new IDs are msg_00…-prefixed. OpenChamber's transcript store sorts and merges messages by message-ID string comparison (the J6/Q6 comparators and gb/nL/eL/tL/X6 helpers in the web bundle), with eL/tL doing binary-search insertion keyed on ID. For any session containing both ID namespaces, string order is 00… < f7… < ff…, so new messages sort to the top of the transcript and the visible "end" stays at the last pre-upgrade message.

Example: a 314-message session spanning the upgrade — the actual newest message (created the day after the upgrade) sorts to index 50 of 314, and the bottom of the transcript shows content from the day before.

Suggested fix: order transcript messages by time.created (falling back to ID for ties) instead of message-ID string order, or keep message IDs monotonic/backward-compatible across releases so ID order remains chronological.

Plugins

Home Assistant add-on

OpenCode version

1.18.16

Steps to reproduce

No response

Screenshot and/or share link

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Operating System

HAOS

Terminal

No response