fix: reduce log files limit and refine explore group streaming fade behavior

src/apps/desktop/src/lib.rs

@@ -144,7 +144,7 @@ pub async fn run() {
                 .level_for("portable_pty", log::LevelFilter::Info)
                 .level_for("russh", log::LevelFilter::Info)
                 .targets(log_targets)
-                .rotation_strategy(RotationStrategy::KeepSome(30))
+                .rotation_strategy(RotationStrategy::KeepSome(3))
                 .max_file_size(10 * 1024 * 1024)
                 .timezone_strategy(TimezoneStrategy::UseLocal)
                 .clear_format()

src/apps/desktop/src/logging.rs

@@ -12,7 +12,7 @@ use std::thread;
 use tauri_plugin_log::{fern, Target, TargetKind};
 
 const SESSION_DIR_PATTERN: &str = r"^\d{8}T\d{6}$";
-const MAX_LOG_SESSIONS: usize = 50;
+const MAX_LOG_SESSIONS: usize = 10;
 static SESSION_LOG_DIR: OnceLock<PathBuf> = OnceLock::new();
 // Default to Debug in early development for easier diagnostics
 static CURRENT_LOG_LEVEL: AtomicU8 = AtomicU8::new(level_filter_to_u8(log::LevelFilter::Debug));

src/web-ui/src/flow_chat/components/modern/ExploreGroupRenderer.tsx

@@ -3,7 +3,7 @@
  * Renders merged explore-only rounds as a collapsible region.
  */
 
-import React, { useRef, useMemo, useCallback, useEffect } from 'react';
+import React, { useRef, useMemo, useCallback, useEffect, useState } from 'react';
 import { ChevronRight } from 'lucide-react';
 import { useTranslation } from 'react-i18next';
 import type { FlowItem, FlowToolItem, FlowTextItem, FlowThinkingItem } from '../../types/flow-chat';
@@ -26,6 +26,7 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
 }) => {
   const { t } = useTranslation('flow-chat');
   const containerRef = useRef<HTMLDivElement>(null);
+  const [scrollState, setScrollState] = useState({ hasScroll: false, atTop: true, atBottom: true });
 
   const { 
     exploreGroupStates, 
@@ -61,6 +62,19 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
   const isCollapsed = !isExpanded;
   const allowManualToggle = !isGroupStreaming;
 
+  const checkScrollState = useCallback(() => {
+    const el = containerRef.current;
+    if (!el) {
+      return;
+    }
+
+    setScrollState({
+      hasScroll: el.scrollHeight > el.clientHeight + 1,
+      atTop: el.scrollTop <= 5,
+      atBottom: el.scrollTop + el.clientHeight >= el.scrollHeight - 5,
+    });
+  }, []);
+
   useEffect(() => {
     if (isGroupStreaming && !hasExplicitState) {
       applyExpandedState(false, true, () => {
@@ -95,10 +109,39 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
       requestAnimationFrame(() => {
         if (containerRef.current) {
           containerRef.current.scrollTop = containerRef.current.scrollHeight;
+          checkScrollState();
         }
       });
     }
-  }, [allItems, isCollapsed, isGroupStreaming]);
+  }, [allItems, checkScrollState, isCollapsed, isGroupStreaming]);
+
+  useEffect(() => {
+    if (!isExpanded) {
+      setScrollState({ hasScroll: false, atTop: true, atBottom: true });
+      return;
+    }
+
+    const el = containerRef.current;
+    if (!el) {
+      return;
+    }
+
+    const frameId = requestAnimationFrame(checkScrollState);
+
+    if (typeof ResizeObserver === 'undefined') {
+      return () => cancelAnimationFrame(frameId);
+    }
+
+    const observer = new ResizeObserver(() => {
+      checkScrollState();
+    });
+    observer.observe(el);
+
+    return () => {
+      cancelAnimationFrame(frameId);
+      observer.disconnect();
+    };
+  }, [allItems, checkScrollState, isExpanded]);
 
   // Build summary text with i18n.
   const displaySummary = useMemo(() => {
@@ -141,6 +184,9 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
     allowManualToggle ? 'explore-region--collapsible' : null,
     isCollapsed ? 'explore-region--collapsed' : 'explore-region--expanded',
     isGroupStreaming ? 'explore-region--streaming' : null,
+    scrollState.hasScroll ? 'explore-region--has-scroll' : null,
+    scrollState.atTop ? 'explore-region--at-top' : null,
+    scrollState.atBottom ? 'explore-region--at-bottom' : null,
   ].filter(Boolean).join(' ');
   return (
     <div
@@ -156,7 +202,7 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
       )}
       <div className="explore-region__content-wrapper">
         <div className="explore-region__content-inner">
-          <div ref={containerRef} className="explore-region__content">
+          <div ref={containerRef} className="explore-region__content" onScroll={checkScrollState}>
             {allItems.map((item, idx) => (
               <ExploreItemRenderer
                 key={item.id}

src/web-ui/src/flow_chat/components/modern/ExploreRegion.scss

@@ -137,9 +137,18 @@
 
 // ==================== Streaming adjustments ====================
 
-// Top/bottom gradient masks during streaming.
+// Top gradient mask during streaming.
 .explore-region--expanded.explore-region--streaming {
-  // Top mask
+  &::before {
+    content: none;
+  }
+
+  &::after {
+    content: none;
+  }
+}
+
+.explore-region--expanded.explore-region--streaming.explore-region--has-scroll:not(.explore-region--at-top) {
   &::before {
     content: '';
     position: absolute;
@@ -158,7 +167,13 @@
     );
   }
 
-  // Bottom mask
+  // Non-collapsible has no header, start mask from the very top.
+  &:not(.explore-region--collapsible)::before {
+    top: 0;
+  }
+}
+
+.explore-region--expanded.explore-region--streaming.explore-region--has-scroll:not(.explore-region--at-bottom) {
   &::after {
     content: '';
     position: absolute;
@@ -175,11 +190,6 @@
       transparent 100%
     );
   }
-
-  // Non-collapsible has no header, start mask from the very top.
-  &:not(.explore-region--collapsible)::before {
-    top: 0;
-  }
 }
 
 // Limit height and enable scroll during streaming.