Load complete chat history when reaching the top (#2481)

* fix(chat): load older timeline history consistently

Pagination depended on scroll events, so short or compacted initial pages could never request older history. Reevaluate edge visibility as layout and history change, and standardize loading indicators on the canonical app spinner.

* fix(chat): keep older history loading reliably

Use authoritative timeline cursor progress so merged rows cannot stall pagination. Wait for bottom anchoring before evaluating the history edge, and re-arm retries on a fresh upward gesture without automatic failure loops.

packages/app/src/composer/index.tsx

@@ -1,8 +1,8 @@
+import { LoadingSpinner } from "@/components/ui/loading-spinner";
 import {
   View,
   Pressable,
   Text,
-  ActivityIndicator,
   StyleSheet as RNStyleSheet,
   type PressableStateCallbackType,
 } from "react-native";
@@ -884,7 +884,7 @@ function ComposerCancelButton({
     ? t("composer.cancel.cancelingAgent")
     : t("composer.cancel.stopAgent");
   const icon = isCancellingAgent ? (
-    <ActivityIndicator size="small" color="white" />
+    <LoadingSpinner size="small" color="white" />
   ) : (
     <Square size={buttonIconSize} color="white" fill="white" />
   );
@@ -984,7 +984,7 @@ function ComposerVoiceModeButton({
   const renderTriggerContent = useCallback(
     ({ hovered }: PressableStateCallbackType & { hovered?: boolean }) => {
       if (isVoiceSwitching) {
-        return <ActivityIndicator size="small" color="white" />;
+        return <LoadingSpinner size="small" color="white" />;
       }
       const colorMapping = hovered ? iconForegroundMapping : iconForegroundMutedMapping;
       return <ThemedAudioLines size={buttonIconSize} uniProps={colorMapping} />;

packages/app/src/composer/input/input.tsx

@@ -1,10 +1,10 @@
+import { LoadingSpinner } from "@/components/ui/loading-spinner";
 import {
   View,
   Text,
   TextInput,
   Pressable,
   Platform,
-  ActivityIndicator,
   useWindowDimensions,
   NativeSyntheticEvent,
   TextInputContentSizeChangeEventData,
@@ -445,7 +445,7 @@ function SendButtonContent({
   buttonIconSize: number;
 }) {
   if (isSubmitLoading) {
-    return <ThemedActivityIndicator size="small" uniProps={iconAccentForegroundMapping} />;
+    return <ThemedLoadingSpinner size="small" uniProps={iconAccentForegroundMapping} />;
   }
   if (submitIcon === "return") {
     return <ThemedCornerDownLeft size={buttonIconSize} uniProps={iconAccentForegroundMapping} />;
@@ -2000,7 +2000,7 @@ const ThemedMic = withUnistyles(Mic);
 const ThemedMicOff = withUnistyles(MicOff);
 const ThemedArrowUp = withUnistyles(ArrowUp);
 const ThemedCornerDownLeft = withUnistyles(CornerDownLeft);
-const ThemedActivityIndicator = withUnistyles(ActivityIndicator);
+const ThemedLoadingSpinner = withUnistyles(LoadingSpinner);
 const ThemedTextInput = withUnistyles(TextInput);
 
 const iconForegroundMapping = (theme: Theme) => ({ color: theme.colors.foreground });