[Bug]: Native chat cannot read ZCode session history (sessions list fine, transcript unreadable) #27130

Summary

ZCode sessions appear in the Agent Session History panel (the scan side has full ZCode support, including its ~/.zcode/cli/db/db.sqlite store and the hidden-transcript filter), but opening one in the native chat / resuming it shows no conversation content.

Steps to reproduce

1. Run ZCode CLI against any project (messages persist to ~/.zcode/cli/db/db.sqlite).
2. Open Agent Session History — the ZCode sessions are listed with message counts and previews.
3. Click a session (or toggle native chat on a ZCode terminal) — no conversation content loads.

Expected

ZCode transcripts read through the same OpenCode SQLite reader as OpenCode 1.x, since ZCode's CLI stores an OpenCode-v1-shaped history.

Actual

NATIVE_CHAT_SUPPORTED_AGENT_LIST has no zcode entry, resolveNativeChatTranscriptAgent('zcode') returns null, and the OpenCode transcript database discovery never probes the ZCode store — so every read reports the transcript unavailable.

Notes

• The scan side (session-scanner-zcode-*) already exists on main, so this is only about wiring the chat transcript read path to the same store with the same hidden-row filter.
• Measured on Windows 11 (also applies to macOS/Linux: the store path is under the user home on every platform).

gh search terms used before filing: zcode, native chat, transcript, session history.