"Copy chat" built the Markdown from persisted rows plus a live tail that was
only included while isStreaming. When a turn was interrupted (dropped stream /
"Lost connection" banner) isStreaming flipped false, the live tail was dropped,
and the partial assistant reply visible on screen — whose row often never
persisted — vanished from the export, leaving only the user messages.
- buildChatMarkdown is now live-first: the on-screen `live` messages ARE the
document. Each is matched to a persisted row by id to enrich it with token
usage / error / timestamp; authoritative usage/error already on the live
message win over the row. When `live` is empty it falls back to the persisted
rows (old format preserved). Only the tail assistant is flagged "still
generating", and only when it is genuinely the streaming tail — so the
status==="submitted" window (tail is the user message) never mislabels the
previous, completed answer.
- The on-screen banner (classified error / dropped connection / manual stop) is
flattened to a string in ChatThread, mirrored into liveStateRef alongside the
messages/isStreaming snapshot, and appended at the end of the export.
- handleCopy maps the live messages and passes live/rows/isStreaming/banner.
Tests: chat-markdown rewritten for the live/enrichment/fallback/banner paths and
the submitted-window regression (26); full ai-chat suite green (186). tsc clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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