fix(chat): restore Facebook keyboard avoidance

src/app/chat/hooks/use-chat-keyboard-diagnostics.ts

@@ -44,6 +44,8 @@ export interface ChatKeyboardDebugSnapshot {
   activeFocused: boolean;
   inputBarTop: number | null;
   inputBarBottom: number | null;
+  inputBarPaddingBottom: string | null;
+  keyboardBottomInset: string | null;
   appViewportHeight: string | null;
   appVisibleHeight: string | null;
   appVisibleOffsetTop: string | null;
@@ -157,7 +159,9 @@ function createChatKeyboardDebugSnapshot(
   const platform = PlatformDetector.getPlatformInfo();
   const browser = BrowserDetector.getBrowserInfo();
   const rootStyle = document.documentElement.style;
-  const inputBarRect = containerRef.current?.getBoundingClientRect() ?? null;
+  const inputBar = containerRef.current;
+  const inputBarRect = inputBar?.getBoundingClientRect() ?? null;
+  const inputBarStyle = inputBar ? window.getComputedStyle(inputBar) : null;
 
   return {
     event,
@@ -187,6 +191,9 @@ function createChatKeyboardDebugSnapshot(
     activeFocused: activeElement !== document.body,
     inputBarTop: inputBarRect?.top ?? null,
     inputBarBottom: inputBarRect?.bottom ?? null,
+    inputBarPaddingBottom: inputBarStyle?.paddingBottom ?? null,
+    keyboardBottomInset:
+      inputBar?.style.getPropertyValue("--chat-keyboard-bottom-inset") || null,
     appViewportHeight:
       rootStyle.getPropertyValue("--app-viewport-height") || null,
     appVisibleHeight: