feat: auto-pause chat on scroll, resume at bottom

src/main/config.ts

@@ -64,7 +64,6 @@ export interface AppConfig {
     matchmaker: Keybind;
     matchmakerAccept: Keybind;
     matchmakerCancel: Keybind;
-    pauseChat: Keybind;
     fullscreenToggle: Keybind;
   };
   userscripts: {
@@ -120,7 +119,6 @@ export const DEFAULT_KEYBINDS: AppConfig['keybinds'] = {
   matchmaker:        { key: 'F6',     ctrl: false, shift: false, alt: false },
   matchmakerAccept:  { key: 'Enter',  ctrl: false, shift: false, alt: false },
   matchmakerCancel:  { key: 'Escape', ctrl: false, shift: false, alt: false },
-  pauseChat:         { key: 'F10',    ctrl: false, shift: false, alt: false },
   fullscreenToggle:  { key: 'F11',    ctrl: false, shift: false, alt: false },
 };
 

src/preload/chat.ts

@@ -16,8 +16,11 @@ let observer: MutationObserver | null = null;
 let historyMax = 0;
 let betterChatEnabled = false;
 let reInsertGuard = false;
+let scrollPaused = false;
 let _con: SavedConsole | null = null;
 
+const SCROLL_BOTTOM_THRESHOLD = 30; // px from bottom to consider "at bottom"
+
 function isChatMessage(node: Node): node is HTMLElement {
     return node.nodeType === 1 && (node as HTMLElement).id?.startsWith('chatMsg_');
 }
@@ -83,18 +86,37 @@ function handleMutations(mutations: MutationRecord[]): void {
         }
     }
 
-    // Auto-scroll unless paused
+    // Auto-scroll to bottom unless the user has scrolled up
-    if (chatList && !chatList.classList.contains('kpc-chat-paused')) {
+    if (chatList && !scrollPaused) {
         chatList.scrollTop = chatList.scrollHeight;
     }
 }
 
+function isNearBottom(el: HTMLElement): boolean {
+    return el.scrollHeight - el.scrollTop - el.clientHeight <= SCROLL_BOTTOM_THRESHOLD;
+}
+
+function updatePauseState(): void {
+    if (!chatList) return;
+    const atBottom = isNearBottom(chatList);
+    if (scrollPaused && atBottom) {
+        scrollPaused = false;
+        chatList.classList.remove('kpc-chat-paused');
+    } else if (!scrollPaused && !atBottom) {
+        scrollPaused = true;
+        chatList.classList.add('kpc-chat-paused');
+    }
+}
+
 function tryAttach(): boolean {
     chatList = document.getElementById('chatList');
     if (!chatList) return false;
 
     observer = new MutationObserver(handleMutations);
     observer.observe(chatList, { childList: true });
+
+    chatList.addEventListener('scroll', updatePauseState, { passive: true });
+
     _con?.log('[KCC-Chat] Observer attached to #chatList');
     return true;
 }