perf(tools): cache LoadContextFiles + fix task detail dialog UX

- Cache agent/user context files via existing agentCache/userCache (TTL 5min)
- Extract cachedAgentFiles/cachedUserFiles helpers, DRY readAgentFile/readUserFile
- Move delete button away from close in task detail modal
- Replace native window.confirm with ConfirmDialog component

internal/tools/context_file_interceptor.go

@@ -161,24 +161,7 @@ func (b *ContextFileInterceptor) ReadFile(ctx context.Context, path string) (str
 }
 
 func (b *ContextFileInterceptor) readAgentFile(ctx context.Context, agentID uuid.UUID, fileName string) (string, bool, error) {
-	key := agentID.String()
-	if files, ok := b.agentCache.Get(ctx, key); ok {
-		for _, f := range files {
-			if f.FileName == fileName {
-				return f.Content, true, nil
-			}
-		}
-		return "", true, nil // cached but file not found
-	}
-
-	// Cache miss → load from DB
-	files, err := b.agentStore.GetAgentContextFiles(ctx, agentID)
-	if err != nil {
-		return "", true, err
-	}
-	b.agentCache.Set(ctx, key, files, b.ttl)
-
-	for _, f := range files {
+	for _, f := range b.cachedAgentFiles(ctx, agentID) {
 		if f.FileName == fileName {
 			return f.Content, true, nil
 		}
@@ -187,35 +170,7 @@ func (b *ContextFileInterceptor) readAgentFile(ctx context.Context, agentID uuid
 }
 
 func (b *ContextFileInterceptor) readUserFile(ctx context.Context, agentID uuid.UUID, userID, fileName string) (string, bool, error) {
-	key := agentID.String() + ":" + userID
-
-	if files, ok := b.userCache.Get(ctx, key); ok {
-		for _, f := range files {
-			if f.FileName == fileName {
-				return f.Content, true, nil
-			}
-		}
-		return "", true, nil
-	}
-
-	// Cache miss → load from DB
-	files, err := b.agentStore.GetUserContextFiles(ctx, agentID, userID)
-	if err != nil {
-		return "", true, err
-	}
-
-	// Convert to AgentContextFileData for unified cache storage
-	cached := make([]store.AgentContextFileData, len(files))
-	for i, f := range files {
-		cached[i] = store.AgentContextFileData{
-			AgentID:  f.AgentID,
-			FileName: f.FileName,
-			Content:  f.Content,
-		}
-	}
-	b.userCache.Set(ctx, key, cached, b.ttl)
-
-	for _, f := range files {
+	for _, f := range b.cachedUserFiles(ctx, agentID, userID) {
 		if f.FileName == fileName {
 			return f.Content, true, nil
 		}
@@ -337,13 +292,11 @@ func (b *ContextFileInterceptor) WriteFile(ctx context.Context, path, content st
 
 // LoadContextFiles loads context files for a specific user+agent combination.
 // Used by the agent loop to dynamically resolve context files for system prompt.
+// Uses the same agentCache/userCache as ReadFile — invalidated on WriteFile and pubsub events.
 func (b *ContextFileInterceptor) LoadContextFiles(ctx context.Context, agentID uuid.UUID, userID, agentType string) []bootstrap.ContextFile {
 	// Open agent: all files from user_context_files
 	if agentType == store.AgentTypeOpen && userID != "" {
-		files, err := b.agentStore.GetUserContextFiles(ctx, agentID, userID)
-		if err != nil {
-			return nil
-		}
+		files := b.cachedUserFiles(ctx, agentID, userID)
 		var result []bootstrap.ContextFile
 		for _, f := range files {
 			if f.Content == "" {
@@ -362,11 +315,8 @@ func (b *ContextFileInterceptor) LoadContextFiles(ctx context.Context, agentID u
 
 	// Predefined agent: agent files + override USER.md from user
 	if agentType == store.AgentTypePredefined && userID != "" {
-		agentFiles, err := b.agentStore.GetAgentContextFiles(ctx, agentID)
-		if err != nil {
-			return nil
-		}
-		userFiles, _ := b.agentStore.GetUserContextFiles(ctx, agentID, userID)
+		agentFiles := b.cachedAgentFiles(ctx, agentID)
+		userFiles := b.cachedUserFiles(ctx, agentID, userID)
 
 		// Build user file map for override lookup
 		userMap := make(map[string]string, len(userFiles))
@@ -411,10 +361,7 @@ func (b *ContextFileInterceptor) LoadContextFiles(ctx context.Context, agentID u
 	}
 
 	// Fallback: agent-level only
-	agentFiles, err := b.agentStore.GetAgentContextFiles(ctx, agentID)
-	if err != nil {
-		return nil
-	}
+	agentFiles := b.cachedAgentFiles(ctx, agentID)
 	var result []bootstrap.ContextFile
 	for _, f := range agentFiles {
 		if f.Content == "" {
@@ -428,6 +375,45 @@ func (b *ContextFileInterceptor) LoadContextFiles(ctx context.Context, agentID u
 	return result
 }
 
+// cachedAgentFiles returns agent-level context files, using agentCache.
+// Same cache used by readAgentFile — invalidated by WriteFile and pubsub events.
+func (b *ContextFileInterceptor) cachedAgentFiles(ctx context.Context, agentID uuid.UUID) []store.AgentContextFileData {
+	key := agentID.String()
+	if files, ok := b.agentCache.Get(ctx, key); ok {
+		return files
+	}
+	files, err := b.agentStore.GetAgentContextFiles(ctx, agentID)
+	if err != nil {
+		return nil
+	}
+	b.agentCache.Set(ctx, key, files, b.ttl)
+	return files
+}
+
+// cachedUserFiles returns user-level context files, using userCache.
+// Same cache used by readUserFile — invalidated by WriteFile and pubsub events.
+func (b *ContextFileInterceptor) cachedUserFiles(ctx context.Context, agentID uuid.UUID, userID string) []store.AgentContextFileData {
+	key := agentID.String() + ":" + userID
+	if files, ok := b.userCache.Get(ctx, key); ok {
+		return files
+	}
+	files, err := b.agentStore.GetUserContextFiles(ctx, agentID, userID)
+	if err != nil {
+		return nil
+	}
+	// Convert to AgentContextFileData for unified cache storage
+	cached := make([]store.AgentContextFileData, len(files))
+	for i, f := range files {
+		cached[i] = store.AgentContextFileData{
+			AgentID:  f.AgentID,
+			FileName: f.FileName,
+			Content:  f.Content,
+		}
+	}
+	b.userCache.Set(ctx, key, cached, b.ttl)
+	return cached
+}
+
 // InvalidateAgent clears the cache for a specific agent (called from event handler).
 func (b *ContextFileInterceptor) InvalidateAgent(agentID uuid.UUID) {
 	ctx := context.Background()

ui/web/src/pages/teams/task-sections/task-detail-dialog.tsx

@@ -4,6 +4,7 @@ import {
 } from "@/components/ui/dialog";
 import { Badge } from "@/components/ui/badge";
 import { Button } from "@/components/ui/button";
+import { ConfirmDialog } from "@/components/shared/confirm-dialog";
 import { Trash2 } from "lucide-react";
 import { useTranslation } from "react-i18next";
 import { formatDate } from "@/lib/format";
@@ -34,6 +35,8 @@ export function TaskDetailDialog({
   const { t } = useTranslation("teams");
   const [events, setEvents] = useState<TeamTaskEvent[]>([]);
   const [attachments, setAttachments] = useState<TeamTaskAttachment[]>([]);
+  const [confirmDelete, setConfirmDelete] = useState(false);
+  const [deleting, setDeleting] = useState(false);
 
   const loadDetail = useCallback(async () => {
     try {
@@ -53,13 +56,16 @@ export function TaskDetailDialog({
 
   const handleDelete = async () => {
     if (!deleteTask) return;
-    if (!window.confirm(t("tasks.deleteConfirm"))) return;
+    setDeleting(true);
     try {
       await deleteTask(teamId, task.id);
       toast.success(t("toast.taskDeleted"));
       onClose();
     } catch {
       toast.error(t("toast.failedDeleteTask"));
+    } finally {
+      setDeleting(false);
+      setConfirmDelete(false);
     }
   };
 
@@ -70,19 +76,12 @@ export function TaskDetailDialog({
     <Dialog open onOpenChange={() => onClose()}>
       <DialogContent className="max-h-[85vh] w-[95vw] flex flex-col sm:max-w-4xl">
         <DialogHeader>
-          <div className="flex items-center justify-between gap-2">
-            <DialogTitle className="flex items-center gap-2">
-              {task.identifier && (
-                <Badge variant="outline" className="font-mono text-xs">{task.identifier}</Badge>
-              )}
-              {t("tasks.detail.title")}
-            </DialogTitle>
-            {canDelete && (
-              <Button variant="ghost" size="icon" className="h-8 w-8 text-destructive hover:bg-destructive/10" onClick={handleDelete}>
-                <Trash2 className="h-4 w-4" />
-              </Button>
+          <DialogTitle className="flex items-center gap-2">
+            {task.identifier && (
+              <Badge variant="outline" className="font-mono text-xs">{task.identifier}</Badge>
             )}
-          </div>
+            {t("tasks.detail.title")}
+          </DialogTitle>
         </DialogHeader>
 
         <div className="space-y-4 overflow-y-auto min-h-0 -mx-4 px-4 sm:-mx-6 sm:px-6">
@@ -235,6 +234,26 @@ export function TaskDetailDialog({
           )}
 
         </div>
+
+        {canDelete && (
+          <div className="flex justify-end border-t pt-3">
+            <Button variant="destructive" size="sm" onClick={() => setConfirmDelete(true)}>
+              <Trash2 className="mr-1.5 h-3.5 w-3.5" />
+              {t("tasks.delete")}
+            </Button>
+          </div>
+        )}
+
+        <ConfirmDialog
+          open={confirmDelete}
+          onOpenChange={setConfirmDelete}
+          title={t("tasks.delete")}
+          description={t("tasks.deleteConfirm")}
+          confirmLabel={t("tasks.delete")}
+          variant="destructive"
+          onConfirm={handleDelete}
+          loading={deleting}
+        />
       </DialogContent>
     </Dialog>
   );