refactor: Refine Chat Message Processing State Display

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessage.svelte

@@ -17,10 +17,16 @@
 	interface Props {
 		class?: string;
 		message: DatabaseMessage;
+		isLastAssistantMessage?: boolean;
 		siblingInfo?: ChatMessageSiblingInfo | null;
 	}
 
-	let { class: className = '', message, siblingInfo = null }: Props = $props();
+	let {
+		class: className = '',
+		message,
+		isLastAssistantMessage = false,
+		siblingInfo = null
+	}: Props = $props();
 
 	const chatActions = getChatActionsContext();
 
@@ -278,6 +284,7 @@
 		bind:textareaElement
 		class={className}
 		{deletionInfo}
+		{isLastAssistantMessage}
 		{message}
 		messageContent={message.content}
 		onConfirmDelete={handleConfirmDelete}

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessageAgenticContent.svelte

@@ -67,7 +67,7 @@
 		{:else if section.type === AgenticSectionType.TOOL_CALL_STREAMING}
 			{@const streamingIcon = isStreaming ? Loader2 : AlertTriangle}
 			{@const streamingIconClass = isStreaming ? 'h-4 w-4 animate-spin' : 'h-4 w-4 text-yellow-500'}
-			{@const streamingSubtitle = isStreaming ? 'streaming...' : 'incomplete'}
+			{@const streamingSubtitle = isStreaming ? '' : 'incomplete'}
 
 			<CollapsibleContentBlock
 				open={isExpanded(index, section)}
@@ -171,7 +171,7 @@
 			</CollapsibleContentBlock>
 		{:else if section.type === AgenticSectionType.REASONING_PENDING}
 			{@const reasoningTitle = isStreaming ? 'Reasoning...' : 'Reasoning'}
-			{@const reasoningSubtitle = isStreaming ? 'streaming...' : 'incomplete'}
+			{@const reasoningSubtitle = isStreaming ? '' : 'incomplete'}
 
 			<CollapsibleContentBlock
 				open={isExpanded(index, section)}

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessageAssistant.svelte

@@ -33,6 +33,7 @@
 			assistantMessages: number;
 			messageTypes: string[];
 		} | null;
+		isLastAssistantMessage?: boolean;
 		message: DatabaseMessage;
 		messageContent: string | undefined;
 		onCopy: () => void;
@@ -51,6 +52,7 @@
 	let {
 		class: className = '',
 		deletionInfo,
+		isLastAssistantMessage = false,
 		message,
 		messageContent,
 		onConfirmDelete,
@@ -100,6 +102,25 @@
 
 	let displayedModel = $derived(message.model ?? null);
 
+	let isCurrentlyLoading = $derived(isLoading());
+	let isStreaming = $derived(isChatStreaming());
+	let hasNoContent = $derived(!message?.content?.trim());
+	let isActivelyProcessing = $derived(isCurrentlyLoading || isStreaming);
+
+	let showProcessingInfoTop = $derived(
+		message?.role === MessageRole.ASSISTANT &&
+			isActivelyProcessing &&
+			hasNoContent &&
+			isLastAssistantMessage
+	);
+
+	let showProcessingInfoBottom = $derived(
+		message?.role === MessageRole.ASSISTANT &&
+			isActivelyProcessing &&
+			!hasNoContent &&
+			isLastAssistantMessage
+	);
+
 	function handleCopyModel() {
 		void copyToClipboard(displayedModel ?? '');
 	}
@@ -111,7 +132,7 @@
 	});
 
 	$effect(() => {
-		if (isLoading() && !message?.content?.trim()) {
+		if (showProcessingInfoTop || showProcessingInfoBottom) {
 			processingState.startMonitoring();
 		}
 	});
@@ -122,11 +143,13 @@
 	role="group"
 	aria-label="Assistant message with actions"
 >
-	{#if message?.role === MessageRole.ASSISTANT && isLoading() && !message?.content?.trim()}
+	{#if showProcessingInfoTop}
 		<div class="mt-6 w-full max-w-[48rem]" in:fade>
 			<div class="processing-container">
 				<span class="processing-text">
-					{processingState.getPromptProgressText() ?? processingState.getProcessingMessage()}
+					{processingState.getPromptProgressText() ??
+						processingState.getProcessingMessage() ??
+						'Processing...'}
 				</span>
 			</div>
 		</div>
@@ -193,7 +216,19 @@
 		</div>
 	{/if}
 
-	<div class="info my-6 grid gap-4">
+	{#if showProcessingInfoBottom}
+		<div class="mt-4 w-full max-w-[48rem]" in:fade>
+			<div class="processing-container">
+				<span class="processing-text">
+					{processingState.getPromptProgressText() ??
+						processingState.getProcessingMessage() ??
+						'Processing...'}
+				</span>
+			</div>
+		</div>
+	{/if}
+
+	<div class="info my-6 grid gap-4 tabular-nums">
 		{#if displayedModel}
 			<div class="inline-flex flex-wrap items-start gap-2 text-xs text-muted-foreground">
 				{#if isRouter}

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessages.svelte

@@ -100,16 +100,26 @@
 			return [];
 		}
 
-		// Filter out system messages if showSystemMessage is false
 		const filteredMessages = currentConfig.showSystemMessage
 			? messages
 			: messages.filter((msg) => msg.type !== MessageRole.SYSTEM);
 
-		return filteredMessages.map((message) => {
+		let lastAssistantIndex = -1;
+		for (let i = filteredMessages.length - 1; i >= 0; i--) {
+			if (filteredMessages[i].role === MessageRole.ASSISTANT) {
+				lastAssistantIndex = i;
+				break;
+			}
+		}
+
+		return filteredMessages.map((message, index) => {
 			const siblingInfo = getMessageSiblings(allConversationMessages, message.id);
+			const isLastAssistantMessage =
+				message.role === MessageRole.ASSISTANT && index === lastAssistantIndex;
 
 			return {
 				message,
+				isLastAssistantMessage,
 				siblingInfo: siblingInfo || {
 					message,
 					siblingIds: [message.id],
@@ -122,7 +132,12 @@
 </script>
 
 <div class="flex h-full flex-col space-y-10 pt-16 md:pt-24 {className}" style="height: auto; ">
-	{#each displayMessages as { message, siblingInfo } (message.id)}
-		<ChatMessage class="mx-auto w-full max-w-[48rem]" {message} {siblingInfo} />
+	{#each displayMessages as { message, isLastAssistantMessage, siblingInfo } (message.id)}
+		<ChatMessage
+			class="mx-auto w-full max-w-[48rem]"
+			{message}
+			{isLastAssistantMessage}
+			{siblingInfo}
+		/>
 	{/each}
 </div>

tools/server/webui/src/lib/components/app/chat/ChatScreen/ChatScreenProcessingInfo.svelte

@@ -11,7 +11,7 @@
 	let isCurrentConversationLoading = $derived(isLoading());
 	let isStreaming = $derived(isChatStreaming());
 	let hasProcessingData = $derived(processingState.processingState !== null);
-	let processingDetails = $derived(processingState.getProcessingDetails());
+	let processingDetails = $derived(processingState.getTechnicalDetails());
 
 	let showProcessingInfo = $derived(
 		isCurrentConversationLoading || isStreaming || config().keepStatsVisible || hasProcessingData

tools/server/webui/src/lib/hooks/use-processing-state.svelte.ts

@@ -197,11 +197,7 @@ export function useProcessingState(): UseProcessingStateReturn {
 		const details: string[] = [];
 
 		// Always show context info when we have valid data
-		if (
-			typeof stateToUse.contextTotal === 'number' &&
-			stateToUse.contextUsed >= 0 &&
-			stateToUse.contextTotal > 0
-		) {
+		if (stateToUse.contextUsed >= 0 && stateToUse.contextTotal > 0) {
 			const contextPercent = Math.round((stateToUse.contextUsed / stateToUse.contextTotal) * 100);
 
 			details.push(