Invite and friend-chat polish: coding-agent placeholder in a friend's Bot chat (regression of #419), two inconsistent invite UIs, Add friend leftovers, Sharing hint #499

Summary

These are small problems in the invite UI and the friend-chat composer. Each is minor, but together they make sharing feel unfinished:

1. Coding-agent placeholder in a friend's Bot chat (regression of Friend's Bot chat on the receiving home: 'Tool removed' line, turns/steps/tok/s footer, composer placeholder flips to coding copy #419): the composer sometimes shows the coding copy instead of Message Chief (SelfA1233).
2. Two different invite UIs: + New… > Add friend and Bot settings > Sharing make the same invite with different controls and feedback.
3. Add friend panel leftovers: a stale error line, and the panel stays open after a successful accept.
4. The Sharing hint mentions People with access when that list is empty.

Environment

• FlyBot main a7adfe0882d3e37c81616871e24b442bd4a5047f, core + plugins/social + plugins/tree on @deepseek-ai/dsh@0.2.0-rc.2, Node 24.21.0.
• Two fresh installs on one Linux box: A :3090 (owner SelfA1233, @selfa1233.home, one Bot: Chief = @chief.selfa1233.home) and B :3091 (owner SelfB1233, @selfb1233.home, one Bot: Chief = @chief.selfb1233.home). Bot Social prod https://47-80-69-220.sslip.io. Both Chiefs on ark/deepseek-v4-flash.
• Product self-test 2026-10-20, focus C (Invites and grants), browser run 12:37–12:42 Asia/Shanghai, API checks about 12:45 Asia/Shanghai. Screenshots stayed on the test machine; what they show is written out below.

1. Composer placeholder flips to coding copy (regression of #419)

Repro: on B (who accepted A's Chief invite), open Chief SelfA1233 for the first time and look at the composer. Then send a first message and look again.

• Actual: on first open the placeholder read Describe what you want to build, / commands, @ files or sessions. After the first message it read Message or run a task…. At other moments the same chat shows the correct Message Chief (SelfA1233), so it switches between these.
• Screenshot (B, empty chat with A's Chief): the header pill reads Chief (SelfA1233) and the composer shows Message Chief (SelfA1233). It was taken after the coding copy had been seen, so the bad state is transient.
• Expected: a friend's Bot chat never shows coding-agent copy (no build/commands/@ files/sessions wording). It always shows Message <friend's Bot name>, from the first paint on, before and after a send. Friend's Bot chat on the receiving home: 'Tool removed' line, turns/steps/tok/s footer, composer placeholder flips to coding copy #419 fixed the after-send flip, and the first-open state (and maybe the after-send one again) has come back.
• Hunch: the placeholder is picked before the chat is known to be a remote Bot (the first render uses the local-session default), and again by another code path after a send.

2. Two inconsistent invite UIs

• Screenshot (B, Chief settings > Sharing): the hint Invite grants Chief only. Revoke anytime in People with access., the full link https://47-80-69-220.sslip.io/i/…, the buttons Copy link (blue), Copy with instructions and New link, then People with access: Nobody has this Bot yet. Invite a friend to grant it.
• Expected (simple, consistent): one invite component used in both places. It names the Bot, shows the link (or at least a Copied confirmation with the Bot named: Invite link for Chief copied.), and offers the same actions. Add friend can keep a single button but must give the same feedback. The paste box must show enough of a pasted link to recognise it (full width, or wrap).

3. Add friend panel leftovers

• After a failed accept, the red error line stays in the panel until the next action (it is not cleared when the result no longer applies).
• After a successful accept (SelfB1233 shared Chief with you.), the panel stays open until Done is clicked.
• Expected: clear the error as soon as the paste box changes. After a successful accept, show the result for a moment and then close the panel, or keep it open but clear the paste box and focus the new friend's Bot in the list. Either way, the result should not need a second click.

4. Sharing hint with an empty list

Invite grants Chief only. Revoke anytime in People with access. shows even when People with access says Nobody has this Bot yet.. Expected: when the list is empty, show only Invite grants Chief only., and add the Revoke sentence once someone has access. Small, but the current hint points at a control that does not exist yet.

Suggested scope

• plugins/social/client.js: extract the Sharing invite block (link + Copy link / Copy with instructions / New link + Copied.) into one component and use it in the Add friend panel's "Invite a friend" section. Name the Bot in the copy feedback. Fix the paste box width.
• plugins/social/client.js Add friend panel: clear the error on input, and auto-close (or reset) after a successful accept.
• Composer placeholder for remote Bot chats: core ds-bot/client.js placeholder selection, so that a remote (bot.remote) chat always uses Message <name> from the first render on. Add a test that renders a remote Bot chat before and after a send.

Acceptance criteria

• A friend's Bot chat never shows coding-agent placeholder copy (first open, after a send, after a reload).
• Add friend and Sharing use the same invite control, and both confirm a copy naming the Bot.
• A pasted link is readable in the Add friend paste box at the default sidebar width.
• The error line clears on input. A successful accept needs no extra Done click.
• The Sharing hint mentions Revoke only when People with access has someone.

Related: #419 (regressed), #343, #173, #166.