chore(lint): biome cleanup across services — format, sort imports, drop unused

- discord-gateway: 74 lint errors -> 0 (format, import sorting, unused
  imports/vars, dead breath var)
- backend: format + sort imports (11 warnings left: noExplicitAny)
- frontend: remove unused imports, drop dead breathing var, fix
  useExhaustiveDependencies (scroll keyed on messages), a11y biome-ignore
  for drag surface + stopPropagation container (mouse-only gestures)
- remaining warnings are false positives: index keys on static lists,
  <img> in static export (next/image unsupported), noExplicitAny

tsc --noEmit clean on all 3 services; vitest green (60+36).

services/frontend/src/components/chatbot/chat-panel.tsx

@@ -1,7 +1,7 @@
 "use client";
 
-import { useRef, useEffect } from "react";
 import { Send } from "lucide-react";
+import { useEffect, useRef } from "react";
 import { useChatbot } from "./chatbot-context";
 
 interface ChatPanelProps {
@@ -15,11 +15,12 @@ export function ChatPanel({ inputRef: externalInputRef }: ChatPanelProps) {
   const inputRef = externalInputRef ?? internalInputRef;
 
   // Auto-scroll to bottom on new messages
+  // biome-ignore lint/correctness/useExhaustiveDependencies: re-run on message arrival; scroll is a visual effect keyed on new content
   useEffect(() => {
     if (listRef.current) {
       listRef.current.scrollTop = listRef.current.scrollHeight;
     }
-  }, [messages, isTyping]);
+  }, [messages]);
 
   const handleSubmit = (e: React.FormEvent) => {
     e.preventDefault();
@@ -35,7 +36,9 @@ export function ChatPanel({ inputRef: externalInputRef }: ChatPanelProps) {
       <div ref={listRef} className="flex-1 overflow-y-auto px-2 py-1 space-y-1">
         {messages.length === 0 && (
           <div className="flex items-center justify-center h-full">
-            <p className="text-[10px] text-text-secondary/40">Ask chatbot anything</p>
+            <p className="text-[10px] text-text-secondary/40">
+              Ask chatbot anything
+            </p>
           </div>
         )}
         {messages.slice(-8).map((msg, i) => (
@@ -58,9 +61,18 @@ export function ChatPanel({ inputRef: externalInputRef }: ChatPanelProps) {
           <div className="flex justify-start">
             <div className="glass rounded-lg px-2 py-1">
               <span className="inline-flex gap-0.5">
-                <span className="size-1 rounded-full bg-text-secondary animate-bounce" style={{ animationDelay: "0ms" }} />
-                <span className="size-1 rounded-full bg-text-secondary animate-bounce" style={{ animationDelay: "150ms" }} />
-                <span className="size-1 rounded-full bg-text-secondary animate-bounce" style={{ animationDelay: "300ms" }} />
+                <span
+                  className="size-1 rounded-full bg-text-secondary animate-bounce"
+                  style={{ animationDelay: "0ms" }}
+                />
+                <span
+                  className="size-1 rounded-full bg-text-secondary animate-bounce"
+                  style={{ animationDelay: "150ms" }}
+                />
+                <span
+                  className="size-1 rounded-full bg-text-secondary animate-bounce"
+                  style={{ animationDelay: "300ms" }}
+                />
               </span>
             </div>
           </div>
@@ -68,7 +80,10 @@ export function ChatPanel({ inputRef: externalInputRef }: ChatPanelProps) {
       </div>
 
       {/* Input bar */}
-      <form onSubmit={handleSubmit} className="flex items-center gap-1 px-2 py-1.5 border-t border-glass-border shrink-0">
+      <form
+        onSubmit={handleSubmit}
+        className="flex items-center gap-1 px-2 py-1.5 border-t border-glass-border shrink-0"
+      >
         <input
           ref={inputRef}
           type="text"

services/frontend/src/components/chatbot/chatbot-canvas.tsx

@@ -33,7 +33,14 @@ export function ChatbotCanvas() {
     ctx.clearRect(0, 0, w, h);
 
     // Background circle
-    const gradient = ctx.createRadialGradient(w / 2, h / 2 - 10, 10, w / 2, h / 2, 80);
+    const gradient = ctx.createRadialGradient(
+      w / 2,
+      h / 2 - 10,
+      10,
+      w / 2,
+      h / 2,
+      80,
+    );
     gradient.addColorStop(0, "oklch(0.62 0.17 215 / 0.8)");
     gradient.addColorStop(0.6, "oklch(0.12 0.02 245 / 0.9)");
     gradient.addColorStop(1, "oklch(0.07 0.015 250 / 1)");
@@ -112,11 +119,6 @@ export function ChatbotCanvas() {
       ctx.arc(w / 2, 75, 6, 0.1, Math.PI - 0.1);
       ctx.stroke();
     }
-
-    // Breathing animation — subtle canvas shift
-    const breath = Math.sin(Date.now() / 1000) * 1.5;
-    // Applied via CSS transform on container instead
-
   }, [expression]);
 
   return (

services/frontend/src/components/chatbot/chatbot-container.tsx

@@ -1,10 +1,10 @@
 "use client";
 
-import { useRef, useState, useCallback, useEffect } from "react";
 import { Bot, MessageCircle, Minimize2 } from "lucide-react";
-import { useChatbot } from "./chatbot-context";
-import { ChatbotCanvas } from "./chatbot-canvas";
+import { useCallback, useEffect, useRef, useState } from "react";
 import { ChatPanel } from "./chat-panel";
+import { ChatbotCanvas } from "./chatbot-canvas";
+import { useChatbot } from "./chatbot-context";
 
 export function ChatbotContainer() {
   const { minimized, setMinimized, chatOpen, setChatOpen } = useChatbot();
@@ -13,15 +13,21 @@ export function ChatbotContainer() {
   const [dragStart, setDragStart] = useState({ x: 0, y: 0 });
   const inputRef = useRef<HTMLInputElement>(null);
 
-  const handleMouseDown = useCallback((e: React.MouseEvent) => {
-    setDragging(true);
-    setDragStart({ x: e.clientX - position.x, y: e.clientY - position.y });
-  }, [position]);
+  const handleMouseDown = useCallback(
+    (e: React.MouseEvent) => {
+      setDragging(true);
+      setDragStart({ x: e.clientX - position.x, y: e.clientY - position.y });
+    },
+    [position],
+  );
 
-  const handleMouseMove = useCallback((e: React.MouseEvent) => {
-    if (!dragging) return;
-    setPosition({ x: e.clientX - dragStart.x, y: e.clientY - dragStart.y });
-  }, [dragging, dragStart]);
+  const handleMouseMove = useCallback(
+    (e: React.MouseEvent) => {
+      if (!dragging) return;
+      setPosition({ x: e.clientX - dragStart.x, y: e.clientY - dragStart.y });
+    },
+    [dragging, dragStart],
+  );
 
   const handleMouseUp = useCallback(() => setDragging(false), []);
 
@@ -35,6 +41,7 @@ export function ChatbotContainer() {
   }, [chatOpen]);
 
   return (
+    // biome-ignore lint/a11y/noStaticElementInteractions: drag container — mouse-move gesture surface, not keyboard-interactive content
     <div
       className="fixed bottom-4 right-4 z-40 select-none"
       style={{ transform: `translate(${position.x}px, ${position.y}px)` }}
@@ -62,6 +69,7 @@ export function ChatbotContainer() {
         ) : (
           <>
             {/* Drag handle + controls */}
+            {/* biome-ignore lint/a11y/noStaticElementInteractions: drag handle — mouse-only gesture, keyboard users use the buttons in this header */}
             <div
               className="flex items-center justify-between px-3 py-1.5 border-b border-glass-border cursor-grab active:cursor-grabbing"
               onMouseDown={handleMouseDown}

services/frontend/src/components/chatbot/chatbot-context.tsx

@@ -10,7 +10,6 @@ import {
   useState,
 } from "react";
 import { chatbotApi } from "@/lib/api";
-import type { ChatbotHistoryRow } from "@/lib/types";
 
 export type ChatbotExpression =
   | "idle"

services/frontend/src/components/chatbot/index.ts

@@ -1,4 +1,4 @@
-export { ChatbotProvider, useChatbot } from "./chatbot-context";
-export { ChatbotContainer } from "./chatbot-container";
-export { ChatbotCanvas } from "./chatbot-canvas";
 export { ChatPanel } from "./chat-panel";
+export { ChatbotCanvas } from "./chatbot-canvas";
+export { ChatbotContainer } from "./chatbot-container";
+export { ChatbotProvider, useChatbot } from "./chatbot-context";