Enter key sends messages; admins can chat with Violet

- Add keydown listener: Enter submits, Shift+Enter inserts newline
- Allow admin users (even guests) to PM Violet

app.py

@@ -601,7 +601,7 @@ def on_pm_message(data):
     
     # Route to AI if recipient is Violet
     if room.endswith(f":{AI_BOT_NAME.lower()}"):
-        if not user.get("user_id"):
+        if not user.get("user_id") and not user.get("is_admin"):
             emit("error", {"msg": "You must be registered to chat with Violet."}); return
         if not user.get("has_ai_access") and user.get("ai_messages_used", 0) >= AI_FREE_LIMIT:
             emit("pm_message", {"from": AI_BOT_NAME, "text": "ai_limit_reached", "room": room, "system": True}, to=sid)

static/chat.js

@@ -428,6 +428,14 @@ messageForm.addEventListener("submit", async (e) => {
     messageInput.style.height = "auto";
 });
 
+// Enter to send, Shift+Enter for newline
+messageInput.addEventListener("keydown", (e) => {
+    if (e.key === "Enter" && !e.shiftKey) {
+        e.preventDefault();
+        messageForm.requestSubmit();
+    }
+});
+
 // Auto-expand textarea
 messageInput.addEventListener("input", () => {
     messageInput.style.height = "auto";