ai-partner: mini-conversation component (inside peek)

[CraigBuckmaster]

Parent epic: #1446 (Amicus — AI Study Partner v1)
Phase: 3 · Size: M · Depends on: #1462 (peek), #1455 (streaming chat)

A 2-3 turn mini-conversation experience that lives inside the FAB peek sheet. Reuses the streaming and citation infrastructure from #1455 but keeps thread state ephemeral (not persisted until user promotes to a full thread via #1464).

---

Files to create

• app/src/components/amicus/PeekMiniConversation.tsx — the component
• app/src/hooks/usePeekConversation.ts — ephemeral conversation state hook
• app/src/components/amicus/__tests__/PeekMiniConversation.test.tsx

Files to modify

• app/src/components/amicus/AmicusPeekSheet.tsx — mount PeekMiniConversation when a chip or input triggers it

---

Ephemeral state

Conversation in the peek is NOT persisted to user.db until user taps "Continue in Amicus tab →" (#1464). Before that, it lives in component/hook state only. If user dismisses the peek without promoting, the conversation is discarded.

This is a deliberate UX choice: the peek is quick-and-disposable; if a conversation is worth keeping, the user explicitly escalates it.

usePeekConversation hook

export interface PeekMessage {
  role: 'user' | 'assistant';
  content: string;
  citations?: AmicusCitation[];
  isStreaming?: boolean;
}

export interface UsePeekConversation {
  messages: PeekMessage[];
  isStreaming: boolean;
  turnCount: number;                    // 0, 1, 2, 3
  error: AmicusError | null;
  send: (text: string, chapterRef?: ChapterRef) => Promise<void>;
  reset: () => void;                    // clear conversation
  snapshotForPromotion: () => PeekMessage[];  // called by #1464
}

Turn counting: a "turn" = user message + assistant response. At turn 3, the UI surfaces the handoff CTA. Send is not disabled at turn 3 — user can still continue, but handoff is strongly suggested.

Streaming: reuses streamChat from #1455 (same proxy endpoint). The difference is purely state location — messages live in hook memory, not user.db.

Component layout

Rendered inside the peek sheet below the chip area (chips hide once conversation starts).

┌─────────────────────────────────────┐
│ [drag handle]                       │
│ Amicus · Romans 9                   │
│ ─────────────────────────────────── │
│ [user bubble]                       │
│ [assistant bubble streaming...]     │
│ [follow-up chip] [chip] [chip]      │
│ ─────────────────────────────────── │
│ At turn 3:                          │
│ ┌─ Continue in Amicus tab → ──────┐ │
│ └─────────────────────────────────┘ │
│ ─────────────────────────────────── │
│ [input field]                  [→]  │
└─────────────────────────────────────┘

Reuses AssistantMessageBubble, UserMessageBubble, CitationPill, FollowUpChips from #1455. Do not duplicate rendering logic.

Differences from full thread

• Auto-collapses if peek is closed (lose ephemeral state)
• No thread title, no back button, no thread-level actions (pin/delete/rename)
• Scroll contained within peek — doesn't interfere with underlying screen scroll

Citation interactions

Citation pill taps in the peek do navigate to source (via #1456). This dismisses the peek and navigates the underlying stack — user can then reopen the FAB to return.

---

Error states

• Rate limit 429 → inline banner in peek: "You've used your monthly Amicus queries. Upgrade to Amicus+ or wait until [date]." + upgrade CTA
• Offline → inline banner: "Amicus needs a connection."
• Other errors → inline banner with retry

No error state collapses the peek — user can always dismiss manually.

---

Performance

• First token ≤ 1.5s (same as full tab, uses same proxy)
• Sheet height transitions smoothly as conversation grows
• Streaming does not cause peek to re-layout its container (use internal scroll)

---

Acceptance criteria

• Tapping a chip triggers mini-conversation; user message bubble appears immediately
• Assistant streams into bubble token-by-token (reuses ai-partner: streaming chat UI with citation pills #1455 infrastructure)
• Citation pills render and navigate correctly (reuses ai-partner: streaming chat UI with citation pills #1455/ai-partner: citation → source navigation #1456)
• At turn 3, "Continue in Amicus tab →" CTA appears
• Closing peek discards conversation (verify via fresh reopen — empty state restored)
• Rate limit / offline errors render inline banners correctly
• Sheet expands to 85% snap when conversation has ≥ 1 turn (peek-to-full promotion)
• No duplicate message rendering logic (reuses ai-partner: streaming chat UI with citation pills #1455 components)
• Component tests cover: send, streaming, turn counting, error rendering, reset
• No any types; lint clean

Out of scope

• Persistence → only happens on promotion (ai-partner: continue-in-tab handoff from peek (re-land with callback pattern) #1464)
• Thread-level features → full Amicus tab concerns