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/components/file-explorer-pane.tsx

@@ -2,7 +2,6 @@ import { useCallback, useEffect, useMemo, useRef, type ReactElement, type RefObj
 import { useQuery } from "@tanstack/react-query";
 import { useTranslation } from "react-i18next";
 import {
-  ActivityIndicator,
   FlatList,
   ListRenderItemInfo,
   Pressable,
@@ -12,7 +11,7 @@ import {
   type StyleProp,
   type ViewStyle,
 } from "react-native";
-import { StyleSheet, useUnistyles } from "react-native-unistyles";
+import { StyleSheet, useUnistyles, withUnistyles } from "react-native-unistyles";
 import { WORKSPACE_SECONDARY_HEADER_HEIGHT } from "@/constants/layout";
 import * as Clipboard from "expo-clipboard";
 import { ChevronDown, Eye, EyeOff, RotateCw } from "lucide-react-native";
@@ -24,6 +23,7 @@ import {
   WORKSPACE_FILE_ROW_VERTICAL_PADDING,
 } from "@/components/tree-primitives";
 import { LoadingSpinner } from "@/components/ui/loading-spinner";
+import type { Theme } from "@/styles/theme";
 import type { AgentFileExplorerState, ExplorerEntry } from "@/stores/session-store";
 import { useSessionStore } from "@/stores/session-store";
 import { FileActionsMenu } from "@/components/file-actions-menu";
@@ -42,6 +42,11 @@ const SORT_OPTIONS: { value: SortOption }[] = [
   { value: "size" },
 ];
 
+const ThemedLoadingSpinner = withUnistyles(LoadingSpinner);
+const foregroundMutedColorMapping = (theme: Theme) => ({
+  color: theme.colors.foregroundMuted,
+});
+
 function formatFileSize({ size }: { size: number }): string {
   if (size < 1024) {
     return `${size} B`;
@@ -163,7 +168,9 @@ function TreeRowItem({
             if (!isDirectory) {
               return <MaterialFileIcon fileName={entry.name} size={16} />;
             }
-            if (loading) return <ActivityIndicator size="small" />;
+            if (loading) {
+              return <ThemedLoadingSpinner size="small" uniProps={foregroundMutedColorMapping} />;
+            }
             return <TreeChevron expanded={isExpanded} />;
           })()}
         </View>
@@ -549,7 +556,7 @@ function FileExplorerPaneContent(props: FileExplorerPaneContentProps) {
   if (showInitialLoading) {
     return (
       <View style={styles.centerState}>
-        <ActivityIndicator size="small" />
+        <ThemedLoadingSpinner size="small" uniProps={foregroundMutedColorMapping} />
         <Text style={styles.loadingText}>{t("workspace.fileExplorer.states.loading")}</Text>
       </View>
     );