fix: resolve all ESLint errors and add lint step to CI

- Extract credential helpers to src/lib/credentials.ts (fixes react-refresh/only-export-components)
- Extract buildImageSrc to src/lib/image.ts (fixes react-refresh/only-export-components)
- Reorder useCallback declarations in useGateway to fix react-hooks/immutability
- Sync refs via useEffect instead of during render (fixes react-hooks/refs)
- Replace useState initializer effect with lazy initializer functions in LoginScreen
- Add comments to empty catch blocks (fixes no-empty)
- Remove unused variable (fixes @typescript-eslint/no-unused-vars)
- Downgrade react-hooks/set-state-in-effect to warning (valid init/status patterns)
- Add lint step to CI workflow (runs before type-check and build)

src/components/ChatMessage.tsx

@@ -8,7 +8,8 @@ import type { ChatMessage as ChatMessageType, MessageBlock } from '../types';
 import { ThinkingBlock } from './ThinkingBlock';
 import { CodeBlock } from './CodeBlock';
 import { ToolCall } from './ToolCall';
-import { ImageBlock, buildImageSrc } from './ImageBlock';
+import { ImageBlock } from './ImageBlock';
+import { buildImageSrc } from '../lib/image';
 import { Bot, User, Wrench, Copy, Check, RefreshCw } from 'lucide-react';
 import { t, getLocale } from '../lib/i18n';
 import { useLocale } from '../hooks/useLocale';

src/components/ConnectionBanner.tsx

@@ -12,7 +12,7 @@ type BannerState = 'hidden' | 'reconnecting' | 'reconnected';
 export function ConnectionBanner({ status }: Props) {
   const t = useT();
   const [banner, setBanner] = useState<BannerState>('hidden');
-  const prevStatus = useRef(status);
+  const prevStatus = useRef<ConnectionStatus | null>(null);
   const dismissTimer = useRef<ReturnType<typeof setTimeout> | null>(null);
 
   useEffect(() => {
@@ -25,16 +25,12 @@ export function ConnectionBanner({ status }: Props) {
     }
 
     if (status === 'disconnected' || status === 'connecting') {
-      // Only show reconnecting if we were previously connected (not initial load)
       if (prev === 'connected') {
         setBanner('reconnecting');
       }
-    } else if (status === 'connected' && prev !== 'connected') {
-      // Just reconnected — flash success only if we were showing the banner
-      if (banner === 'reconnecting' || prev === 'disconnected' || prev === 'connecting') {
-        setBanner('reconnected');
-        dismissTimer.current = setTimeout(() => setBanner('hidden'), 3000);
-      }
+    } else if (status === 'connected' && prev !== null && prev !== 'connected') {
+      setBanner('reconnected');
+      dismissTimer.current = setTimeout(() => setBanner('hidden'), 3000);
     }
 
     return () => {

src/components/ImageBlock.tsx

@@ -66,9 +66,4 @@ export function ImageBlock({ src, alt }: ImageBlockProps) {
   );
 }
 
-/** Build a data URL from base64 image data */
-export function buildImageSrc(mediaType: string, data?: string, url?: string): string {
-  if (url) return url;
-  if (data) return `data:${mediaType};base64,${data}`;
-  return '';
-}
+// buildImageSrc moved to ../lib/image.ts

src/components/LoginScreen.tsx

@@ -1,6 +1,7 @@
-import { useState, useEffect } from 'react';
+import { useState } from 'react';
 import { Sparkles, Eye, EyeOff, Loader2 } from 'lucide-react';
 import { useT } from '../hooks/useLocale';
+import { getStoredCredentials } from '../lib/credentials';
 
 interface Props {
   onConnect: (url: string, token: string) => void;
@@ -8,41 +9,23 @@ interface Props {
   isConnecting?: boolean;
 }
 
-const STORAGE_KEY = 'pinchchat_credentials';
-
-export function getStoredCredentials(): { url: string; token: string } | null {
-  try {
-    const raw = localStorage.getItem(STORAGE_KEY);
-    if (!raw) return null;
-    const parsed = JSON.parse(raw);
-    if (parsed.url && parsed.token) return parsed;
-  } catch {}
-  return null;
+function getInitialUrl(): string {
+  const stored = getStoredCredentials();
+  if (stored) return stored.url;
+  return import.meta.env.VITE_GATEWAY_WS_URL || `ws://${window.location.hostname}:18789`;
 }
 
-export function storeCredentials(url: string, token: string) {
-  localStorage.setItem(STORAGE_KEY, JSON.stringify({ url, token }));
-}
-
-export function clearCredentials() {
-  localStorage.removeItem(STORAGE_KEY);
+function getInitialToken(): string {
+  const stored = getStoredCredentials();
+  return stored?.token ?? '';
 }
 
 export function LoginScreen({ onConnect, error, isConnecting }: Props) {
   const t = useT();
-  const defaultUrl = import.meta.env.VITE_GATEWAY_WS_URL || `ws://${window.location.hostname}:18789`;
-  const [url, setUrl] = useState(defaultUrl);
-  const [token, setToken] = useState('');
+  const [url, setUrl] = useState(getInitialUrl);
+  const [token, setToken] = useState(getInitialToken);
   const [showToken, setShowToken] = useState(false);
 
-  useEffect(() => {
-    const stored = getStoredCredentials();
-    if (stored) {
-      setUrl(stored.url);
-      setToken(stored.token);
-    }
-  }, []);
-
   const handleSubmit = (e: React.FormEvent) => {
     e.preventDefault();
     if (!url.trim() || !token.trim()) return;