First message in a new friend's remote chat is silently dropped #66

Problem

The first message in a brand-new friend's remote chat is silently dropped: the reply is empty, nothing is forwarded to the friend, and no error is shown. The second message works.

Cause

On the first turn of a new chat, dsh-agent-instructions appends an AGENTS.md baseline message after the user's text:

{ role: 'user', source: { kind: 'agent-instructions', form: 'instructions', baseline: true } }

remoteTurn in core/src/host/remote-chat.js picks the last user message that is not a context snapshot. isContextSnapshot only recognizes form === 'snapshot' and the time-context kinds, so the baseline counts as the last message. remoteTurn then returns { kind: 'none' }, the reply is empty, and forward() is never called. On the second message the baseline is already in history, so the real text is last again and it works.

Notice-form messages (dsh-plan-mode, dsh-repeat-tool-reminder, which use form: 'notice') are the same class of bug.

Repro

remoteTurn([user('hi', { kind: 'user' }), agentInstructionsMsg]) // -> { kind: 'none' }, expected { kind: 'send', text: 'hi' }

Impact

Only the flybot-remote/<handle> model route uses remoteTurn, so @flybot/tree is not affected.

Found while recording the social demo (PR #65).

Fix

Treat the snapshot, instructions and notice forms, and the agent-instructions kind, as context (not a whitelist of user messages). PR to follow. It goes through the patch layer (patches/ds-bot/0005-social-seams.patch), not ds-bot/.