TUI: "Expected a string starting with ses, got %7Bid%7D" in 1.18.13 — stale frame/rendering artifact after question dismissed in plan mode

Description

Summary

Still reproducible on the latest stable 1.18.13 (brew, macOS arm64, kitty terminal). Same error signature as #29868, different trigger path: dismissing/rejecting a question in plan mode leaves stale rendered text on screen (input box + outside), which only disappears after typing.

Reproduction

1. Run opencode in plan mode
2. A question prompt is raised and dismissed/rejected by the mode restriction
3. Stale text remains on screen, e.g. ses_xxx:msg_xxx; typing in the input box clears the in-box residue, but residue outside the box persists
4. Log shows: Expected a string starting with "ses", got "%7Bid%7D" (%7Bid%7D is URL-encoded {id} — a template placeholder passed un-interpolated as a session ID)

Evidence

ERROR message=failed error="Expected a string starting with "ses", got "%7Bid%7D" (cause: ...)"
at (/$bunfs/root/chunk-datjqaqc.js:25:10206)
Observed on both 1.18.11 and 1.18.13 (same stack location). Also observed two opencode processes spinning at 100% CPU for ~1.5 days after a session got stuck (likely related to the infinite render loop in #29868).

Environment

• opencode 1.18.13 (brew)
• macOS 26.5.2 (arm64), kitty terminal
• Log: ~/.local/share/opencode/log/opencode.log

Plugins

No response

OpenCode version

No response

Steps to reproduce

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Screenshot and/or share link

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Operating System

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Terminal

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