[pratikbuilds]

ConversationThread renders a reply conversation headed by its parent message, with a divider counting the replies, built from the same parts as the main conversation through a render prop. Each thread has its own Conversation, so a reply settles at the top of its own log, and in a keep-mounted panel tab a thread keeps its place and the host's draft while the reader switches tabs. The thread's PromptInput sits below the log, and aria-label or aria-labelledby names the log.

Stacked on #13: review only this commit. Part of corbitsdev#94.

Notes for review

• Props: parent, replies, renderMessage(message), sentId (this thread only), scrollPolicy (default settle), labels {log, replies(count)}; aria-label or aria-labelledby name the log; children (the thread's PromptInput) sit below the log. Stateless: no "use client".
• A thread that is unmounted, or given no size while hidden, loses its place: use PanelContent keepMounted.

Verification

• This commit passes bun run typecheck and bun run lint on its own (the stack is checked commit by commit).
• At the top of the stack: bun run check, bun run build, bun run dep-guard, bun run contrast-test and bun run test:e2e (Playwright specs and the Storybook axe sweep in light and dark) pass.

Closes corbitsdev#108

[pratikbuilds]

Moved upstream: corbitsdev#126