feat: per-user assistant name and system prompt customization

Each user can rename the AI assistant and edit their own system prompt in Settings.

src/modules/agent/components/assistant-bubble.tsx

@@ -7,9 +7,10 @@ import { AssistantPanel } from "./assistant-panel";
 type Props = {
   configured: boolean;
   userId: string;
+  assistantName: string;
 };
 
-export function AssistantBubble({ configured, userId }: Props) {
+export function AssistantBubble({ configured, userId, assistantName }: Props) {
   const [open, setOpen] = useState(false);
 
   return (
@@ -18,31 +19,36 @@ export function AssistantBubble({ configured, userId }: Props) {
         <div
           className="assistant-bubble-panel"
           role="dialog"
-          aria-label="Assistant"
+          aria-label={assistantName}
           aria-modal="false"
         >
           <div className="assistant-bubble-header">
             <div>
-              <div className="serif text-[15px] font-medium tracking-tight">Assistant</div>
+              <div className="serif text-[15px] font-medium tracking-tight">{assistantName}</div>
               <div className="muted text-[11px]">Household helper</div>
             </div>
             <button
               type="button"
               className="assistant-bubble-close"
-              aria-label="Close assistant"
+              aria-label={`Close ${assistantName}`}
               onClick={() => setOpen(false)}
             >
               <X className="size-4" />
             </button>
           </div>
-          <AssistantPanel key={userId} configured={configured} userId={userId} />
+          <AssistantPanel
+            key={userId}
+            configured={configured}
+            userId={userId}
+            assistantName={assistantName}
+          />
         </div>
       ) : null}
 
       <button
         type="button"
         className="assistant-bubble-trigger"
-        aria-label={open ? "Close assistant" : "Open assistant"}
+        aria-label={open ? `Close ${assistantName}` : `Open ${assistantName}`}
         aria-expanded={open}
         onClick={() => setOpen((current) => !current)}
       >

src/modules/agent/components/assistant-panel.tsx

@@ -15,9 +15,10 @@ import {
 type Props = {
   configured: boolean;
   userId: string;
+  assistantName: string;
 };
 
-export function AssistantPanel({ configured, userId }: Props) {
+export function AssistantPanel({ configured, userId, assistantName }: Props) {
   const [messages, setMessages] = useState<AssistantChatMessage[]>(() => loadAssistantChat(userId));
   const [input, setInput] = useState("");
   const [error, setError] = useState<string | null>(null);
@@ -144,7 +145,7 @@ export function AssistantPanel({ configured, userId }: Props) {
                 style={message.role === "assistant" ? { borderColor: "var(--hair)" } : undefined}
               >
                 <div className="eyebrow mb-0.5 text-[10px]">
-                  {message.role === "user" ? "You" : "Assistant"}
+                  {message.role === "user" ? "You" : assistantName}
                 </div>
                 {message.content}
               </div>
@@ -157,7 +158,7 @@ export function AssistantPanel({ configured, userId }: Props) {
                 aria-live="polite"
                 aria-busy="true"
               >
-                <div className="eyebrow mb-1 text-[10px]">Assistant</div>
+                <div className="eyebrow mb-1 text-[10px]">{assistantName}</div>
                 <div className="flex items-center gap-2 text-[12.5px] text-muted-foreground">
                   <Loader2 className="size-3.5 shrink-0 animate-spin" />
                   <span>{activityLabel ?? "Working…"}</span>
@@ -180,9 +181,9 @@ export function AssistantPanel({ configured, userId }: Props) {
         <Input
           value={input}
           onChange={(event) => setInput(event.target.value)}
-          placeholder="Ask the assistant…"
+          placeholder={`Ask ${assistantName}…`}
           disabled={isPending}
-          aria-label="Assistant message"
+          aria-label={`Message for ${assistantName}`}
           className="h-9"
         />
         <Button type="submit" size="sm" disabled={isPending || !input.trim()} aria-label="Send">

src/modules/agent/server/run.ts

@@ -26,6 +26,7 @@ export type AgentProgressHandler = (event: AgentProgressEvent) => void;
 export async function runAgentChat(options: {
   messages: ClientChatMessage[];
   request: Request;
+  systemPrompt?: string;
   llm?: LlmClient;
   executeTool?: ToolExecutor;
   onProgress?: AgentProgressHandler;
@@ -33,9 +34,10 @@ export async function runAgentChat(options: {
   const llm = options.llm ?? createLlmClient();
   const executeTool = options.executeTool ?? createApiToolExecutor(options.request);
   const onProgress = options.onProgress;
+  const systemPrompt = options.systemPrompt ?? AGENT_SYSTEM_PROMPT;
 
   const transcript: ChatMessage[] = [
-    { role: "system", content: AGENT_SYSTEM_PROMPT },
+    { role: "system", content: systemPrompt },
     ...options.messages.map(
       (message): ChatMessage => ({
         role: message.role,