feat: optional notice slot under composer + fix starter-suggestion crash

Add an optional `notice` prop (React.ReactNode) to AgentDockProps, rendered
as quiet fine-print under the composer. Lets a host app surface a privacy /
data-handling notice next to the input without the dock owning the copy.
Default undefined — no change for apps that don't pass it.

Also fix a latent crash: a "Try saying" starter suggestion called
sendMessage(s) with a single argument, but sendMessage(display, wire)
immediately does wire.trim() — clicking a suggestion threw on undefined.
Pass (s, s) since a suggestion's display and wire text are identical.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/index.tsx

@@ -113,6 +113,11 @@ export interface AgentDockProps {
   hidden?: boolean;
   /** localStorage namespace for the open/closed state. */
   storageKey?: string;
+  /** Optional fine-print rendered under the composer — e.g. a privacy /
+   *  data-handling notice. App-supplied content (the dock stays generic);
+   *  omit for no notice. Kept visually quiet so it doesn't compete with the
+   *  input. */
+  notice?: React.ReactNode;
 }
 
 /* ------------------------------------------------------------------ */
@@ -153,6 +158,7 @@ export function AgentDock({
   onExpand,
   hidden = false,
   storageKey = DEFAULT_STORAGE_KEY,
+  notice,
 }: AgentDockProps) {
   const [open, setOpen] = useState<boolean>(() => {
     if (typeof window === "undefined") return false;
@@ -418,7 +424,7 @@ export function AgentDock({
                             <li key={s}>
                               <button
                                 type="button"
-                                onClick={() => void sendMessage(s)}
+                                onClick={() => void sendMessage(s, s)}
                                 disabled={sending}
                                 className="w-full rounded-lg border border-[var(--border)] bg-[var(--chat-assistant-bg)] px-3 py-2 text-left text-sm leading-snug text-[var(--chat-assistant-fg)] transition-colors hover:border-[var(--primary)] disabled:opacity-60"
                                 data-action="assistant-dock-starter"
@@ -504,6 +510,11 @@ export function AgentDock({
                   )}
                 </button>
               </div>
+              {notice ? (
+                <div className="mt-2 px-0.5 text-[11px] leading-snug text-[var(--foreground)]/50">
+                  {notice}
+                </div>
+              ) : null}
             </div>
           </div>
         </div>