feat(chat): live turn metrics — telemetry reducer + rendering

Consume wire/transport-contract 0.3.0 (step-complete event + timing
fields on usage/tool-result/done). Pure core/telemetry module:
foldMetricEvent (reducer) + derived selectors (stepTps, turnTps, etc).
TelemetryState is pure data, no active-turn tracking — consumers pass
turnId to selectors. ChatStore wires foldMetricEvent into handleDelta
and exposes telemetry + currentTurnId. ChatView shows step-metrics
footer (time/TPS/tokens) on assistant text bubbles and durationMs badge
on tool cards. New TurnSummary component renders turn-level stats
(wall-clock, tokens, steps, TPS) in a DaisyUI stats block. Extended
live-probe to verify telemetry events against bin/up (pending backend
restart). 336 tests, typecheck 0, biome clean, build ok.

6 files changed, 341 insertions, 37 deletions

diff --git a/src/features/chat/index.ts b/src/features/chat/index.ts
index 4f2091a..b096cca 100644
--- a/src/features/chat/index.ts
+++ b/src/features/chat/index.ts
@@ -1,8 +1,10 @@
 export type { RenderedChunk, RenderGroup, ToolBatchEntry } from "../../core/chunks";
 export { groupRenderedChunks } from "../../core/chunks";
+export type { StepMetrics, TelemetryState, TurnMetrics } from "../../core/telemetry";
 export type { ChatTransport, HistorySync } from "./ports";
 export type { ChatStore, ChatStoreDependencies } from "./store.svelte";
 export { createChatStore } from "./store.svelte";
 export { default as ChatView } from "./ui/ChatView.svelte";
 export { default as Composer } from "./ui/Composer.svelte";
 export { default as ModelSelector } from "./ui/ModelSelector.svelte";
+export { default as TurnSummary } from "./ui/TurnSummary.svelte";
diff --git a/src/features/chat/store.svelte.ts b/src/features/chat/store.svelte.ts
index 1d8ab17..58c165f 100644
--- a/src/features/chat/store.svelte.ts
+++ b/src/features/chat/store.svelte.ts
@@ -13,6 +13,8 @@ import {
 	selectChunks,
 	selectMessages,
 } from "../../core/chunks";
+import type { TelemetryState } from "../../core/telemetry";
+import { foldMetricEvent, initialState as telemetryInitialState } from "../../core/telemetry";
 import type { ConversationCache } from "../conversation-cache";
 import type { ChatTransport, HistorySync } from "./ports";
 
@@ -30,6 +32,8 @@ export interface ChatStore {
 	readonly pendingSync: boolean;
 	readonly error: string | null;
 	readonly model: string | undefined;
+	readonly telemetry: TelemetryState;
+	readonly currentTurnId: string | null;
 	handleDelta(msg: ChatDeltaMessage | ChatErrorMessage): void;
 	send(text: string): void;
 	setModel(model: string): void;
@@ -42,6 +46,7 @@ export function createChatStore(deps: ChatStoreDependencies): ChatStore {
 	let _pendingSync = $state(false);
 	let _error = $state<string | null>(null);
 	let _model = $state<string | undefined>(deps.model);
+	let telemetry = $state<TelemetryState>(telemetryInitialState());
 	let disposed = false;
 
 	async function syncTail(): Promise<void> {
@@ -76,6 +81,12 @@ export function createChatStore(deps: ChatStoreDependencies): ChatStore {
 		get model(): string | undefined {
 			return _model;
 		},
+		get telemetry(): TelemetryState {
+			return telemetry;
+		},
+		get currentTurnId(): string | null {
+			return transcript.currentTurnId;
+		},
 
 		handleDelta(msg: ChatDeltaMessage | ChatErrorMessage): void {
 			if (msg.type === "chat.error") {
@@ -89,6 +100,7 @@ export function createChatStore(deps: ChatStoreDependencies): ChatStore {
 				return;
 			}
 			transcript = foldEvent(transcript, msg.event);
+			telemetry = foldMetricEvent(telemetry, msg.event);
 			if (transcript.sealedTurnId !== null) {
 				void syncTail();
 			}
diff --git a/src/features/chat/store.test.ts b/src/features/chat/store.test.ts
index 71781ac..347cdd7 100644
--- a/src/features/chat/store.test.ts
+++ b/src/features/chat/store.test.ts
@@ -393,6 +393,52 @@ describe("createChatStore", () => {
 		store.dispose();
 	});
 
+	it("folding step-complete and usage events populates telemetry", () => {
+		const transport = createFakeTransport();
+		const historySync = createFakeHistorySync();
+		const cache = createFakeCache();
+		const store = createChatStore({
+			conversationId: CONV_ID,
+			transport: transport.impl,
+			historySync: historySync.impl,
+			cache: cache.impl,
+		});
+
+		store.handleDelta(deltaEvent({ type: "turn-start", conversationId: CONV_ID, turnId: "t1" }));
+		store.handleDelta(
+			deltaEvent({
+				type: "step-complete",
+				conversationId: CONV_ID,
+				turnId: "t1",
+				stepId: "t1#0" as StepId,
+				ttftMs: 300,
+				decodeMs: 700,
+				genTotalMs: 1000,
+			}),
+		);
+		store.handleDelta(
+			deltaEvent({
+				type: "usage",
+				conversationId: CONV_ID,
+				turnId: "t1",
+				stepId: "t1#0" as StepId,
+				usage: { inputTokens: 50, outputTokens: 20 },
+			}),
+		);
+
+		const turn = store.telemetry.turns.get("t1");
+		expect(turn).toBeDefined();
+		expect(turn?.steps).toHaveLength(1);
+		const step = turn?.steps.find((s) => s.stepId === ("t1#0" as StepId));
+		expect(step).toBeDefined();
+		expect(step?.ttftMs).toBe(300);
+		expect(step?.decodeMs).toBe(700);
+		expect(step?.usage?.inputTokens).toBe(50);
+		expect(step?.usage?.outputTokens).toBe(20);
+
+		store.dispose();
+	});
+
 	it("handleDelta ignores a chat.delta for a different conversationId", () => {
 		const transport = createFakeTransport();
 		const historySync = createFakeHistorySync();
diff --git a/src/features/chat/ui.test.ts b/src/features/chat/ui.test.ts
index b31cbf1..02d3c5a 100644
--- a/src/features/chat/ui.test.ts
+++ b/src/features/chat/ui.test.ts
@@ -3,9 +3,15 @@ import { render, screen } from "@testing-library/svelte";
 import userEvent from "@testing-library/user-event";
 import { describe, expect, it, vi } from "vitest";
 import type { RenderedChunk } from "../../core/chunks";
+import type { TelemetryState } from "../../core/telemetry";
+import { initialState } from "../../core/telemetry";
 import ChatView from "./ui/ChatView.svelte";
 import Composer from "./ui/Composer.svelte";
 import ModelSelector from "./ui/ModelSelector.svelte";
+import TurnSummary from "./ui/TurnSummary.svelte";
+
+const emptyTelemetry = initialState();
+const noTurnId = null;
 
 describe("ChatView", () => {
 	it("renders a message's text chunk", () => {
@@ -18,7 +24,7 @@ describe("ChatView", () => {
 			},
 		];
 
-		render(ChatView, { props: { chunks } });
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		expect(screen.getByText("Hello world")).toBeInTheDocument();
 	});
@@ -34,7 +40,7 @@ describe("ChatView", () => {
 			},
 		];
 
-		render(ChatView, { props: { chunks } });
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		expect(screen.getByText("Hi there")).toBeInTheDocument();
 		expect(screen.getByText("Hello!")).toBeInTheDocument();
@@ -55,7 +61,7 @@ describe("ChatView", () => {
 			},
 		];
 
-		render(ChatView, { props: { chunks } });
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		expect(screen.getByText("read_file")).toBeInTheDocument();
 		const pre = screen.getByText((content, element) => {
@@ -80,7 +86,7 @@ describe("ChatView", () => {
 			},
 		];
 
-		render(ChatView, { props: { chunks } });
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		expect(screen.getByText("read_file")).toBeInTheDocument();
 		expect(screen.getByText("file contents here")).toBeInTheDocument();
@@ -96,7 +102,7 @@ describe("ChatView", () => {
 			},
 		];
 
-		render(ChatView, { props: { chunks } });
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		const alert = screen.getByRole("alert");
 		expect(alert).toHaveTextContent("Something failed");
@@ -112,7 +118,7 @@ describe("ChatView", () => {
 			},
 		];
 
-		render(ChatView, { props: { chunks } });
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		expect(screen.getByText("Rate limited")).toBeInTheDocument();
 		expect(screen.getByText("[RATE_LIMIT]")).toBeInTheDocument();
@@ -128,7 +134,7 @@ describe("ChatView", () => {
 			},
 		];
 
-		render(ChatView, { props: { chunks } });
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		expect(screen.getByText("System context loaded")).toBeInTheDocument();
 	});
@@ -143,7 +149,7 @@ describe("ChatView", () => {
 			},
 		];
 
-		render(ChatView, { props: { chunks } });
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		// In-flight chunks render at full opacity (no faded "disabled" look).
 		const wrapper = screen.getByText("Streaming...").closest("div");
@@ -151,7 +157,7 @@ describe("ChatView", () => {
 	});
 
 	it("renders empty transcript", () => {
-		render(ChatView, { props: { chunks: [] } });
+		render(ChatView, { props: { chunks: [], telemetry: emptyTelemetry, currentTurnId: noTurnId } });
 
 		const log = screen.getByRole("log");
 		expect(log).toBeInTheDocument();
@@ -199,7 +205,9 @@ describe("ChatView", () => {
 			},
 		];
 
-		const { container } = render(ChatView, { props: { chunks } });
+		const { container } = render(ChatView, {
+			props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId },
+		});
 
 		// One DaisyUI list with two rows (one per call), not separate cards.
 		const lists = container.querySelectorAll("ul.list");
@@ -224,7 +232,9 @@ describe("ChatView", () => {
 			},
 		];
 
-		const { container } = render(ChatView, { props: { chunks } });
+		const { container } = render(ChatView, {
+			props: { chunks, telemetry: emptyTelemetry, currentTurnId: noTurnId },
+		});
 
 		const collapse = container.querySelector(".collapse");
 		expect(collapse).not.toBeNull();
@@ -247,7 +257,9 @@ describe("ChatView", () => {
 			},
 		];
 
-		const { container, rerender } = render(ChatView, { props: { chunks: streaming } });
+		const { container, rerender } = render(ChatView, {
+			props: { chunks: streaming, telemetry: emptyTelemetry, currentTurnId: noTurnId },
+		});
 
 		// Streaming: "Thinking" + loading dots.
 		expect(screen.getByText("Thinking")).toBeInTheDocument();
@@ -269,6 +281,8 @@ describe("ChatView", () => {
 					provisional: false,
 				},
 			],
+			telemetry: emptyTelemetry,
+			currentTurnId: noTurnId,
 		});
 
 		// Completed: "Thoughts", no dots — and the open state survived the transition.
@@ -278,6 +292,118 @@ describe("ChatView", () => {
 		expect(screen.getByRole("checkbox", { name: "Toggle thoughts" })).toBeChecked();
 		expect(container).toHaveTextContent("hmm, all done");
 	});
+
+	it("assistant text shows step metrics footer when step-complete data is available", () => {
+		const chunks: RenderedChunk[] = [
+			{
+				seq: 1,
+				role: "assistant",
+				chunk: { type: "text", text: "Here is my answer" },
+				provisional: false,
+			},
+		];
+
+		const telemetry: TelemetryState = {
+			turns: new Map([
+				[
+					"turn-1",
+					{
+						wallMs: 2500,
+						steps: [
+							{
+								stepId: "turn-1#0" as StepId,
+								genTotalMs: 1200,
+								decodeMs: 1000,
+								usage: { inputTokens: 100, outputTokens: 86 },
+							},
+						],
+					},
+				],
+			]),
+		};
+
+		render(ChatView, { props: { chunks, telemetry, currentTurnId: "turn-1" } });
+
+		expect(screen.getByText("Here is my answer")).toBeInTheDocument();
+		expect(screen.getByText("1.2s")).toBeInTheDocument();
+		expect(screen.getByText("86 t/s")).toBeInTheDocument();
+		expect(screen.getByText("86 tok")).toBeInTheDocument();
+	});
+
+	it("does not show metrics footer when no step data exists", () => {
+		const chunks: RenderedChunk[] = [
+			{
+				seq: 1,
+				role: "assistant",
+				chunk: { type: "text", text: "Still streaming" },
+				provisional: true,
+			},
+		];
+
+		render(ChatView, { props: { chunks, telemetry: emptyTelemetry, currentTurnId: "turn-1" } });
+
+		expect(screen.getByText("Still streaming")).toBeInTheDocument();
+		expect(screen.queryByText("t/s")).toBeNull();
+		expect(screen.queryByText("tok")).toBeNull();
+	});
+});
+
+describe("TurnSummary", () => {
+	it("renders turn stats when telemetry has data", () => {
+		const telemetry: TelemetryState = {
+			turns: new Map([
+				[
+					"turn-1",
+					{
+						wallMs: 4200,
+						steps: [
+							{
+								stepId: "turn-1#0" as StepId,
+								genTotalMs: 2000,
+								decodeMs: 1500,
+								usage: { inputTokens: 500, outputTokens: 300 },
+							},
+							{
+								stepId: "turn-1#1" as StepId,
+								genTotalMs: 1800,
+								decodeMs: 1200,
+								usage: { inputTokens: 600, outputTokens: 200 },
+							},
+						],
+					},
+				],
+			]),
+		};
+
+		render(TurnSummary, { props: { telemetry, turnId: "turn-1" } });
+
+		expect(screen.getByText("Turn")).toBeInTheDocument();
+		expect(screen.getByText("4.2s")).toBeInTheDocument();
+		expect(screen.getByText("Tokens")).toBeInTheDocument();
+		expect(screen.getByText("1,600")).toBeInTheDocument();
+		expect(screen.getByText("Output")).toBeInTheDocument();
+		expect(screen.getByText("500")).toBeInTheDocument();
+		expect(screen.getByText("Input")).toBeInTheDocument();
+		expect(screen.getByText("1,100")).toBeInTheDocument();
+		expect(screen.getByText("Steps")).toBeInTheDocument();
+		expect(screen.getByText("2")).toBeInTheDocument();
+		expect(screen.getByText("TPS")).toBeInTheDocument();
+		expect(screen.getByText("185 t/s")).toBeInTheDocument();
+	});
+
+	it("renders nothing when turnId is null", () => {
+		const { container } = render(TurnSummary, {
+			props: { telemetry: emptyTelemetry, turnId: null },
+		});
+		expect(container.querySelector(".stats")).toBeNull();
+	});
+
+	it("renders nothing when turn metrics not found", () => {
+		const { container } = render(TurnSummary, {
+			props: { telemetry: emptyTelemetry, turnId: "nonexistent" },
+		});
+		expect(container.querySelector(".stats")).toBeNull();
+	});
 });
 
 describe("Composer", () => {
diff --git a/src/features/chat/ui/ChatView.svelte b/src/features/chat/ui/ChatView.svelte
index 3a078fb..6acda53 100644
--- a/src/features/chat/ui/ChatView.svelte
+++ b/src/features/chat/ui/ChatView.svelte
@@ -1,16 +1,27 @@
 <script lang="ts">
 	import { groupRenderedChunks, type RenderedChunk } from "../index";
+	import type { TelemetryState } from "../../../core/telemetry";
+	import { stepMetrics, stepTps } from "../../../core/telemetry";
 
-	let { chunks }: { chunks: readonly RenderedChunk[] } = $props();
+	interface Props {
+		chunks: readonly RenderedChunk[];
+		telemetry: TelemetryState;
+		currentTurnId: string | null;
+	}
+
+	let { chunks, telemetry, currentTurnId }: Props = $props();
 
 	const groups = $derived(groupRenderedChunks(chunks));
 
-	// Stable per-row keys. Thinking blocks get an ordinal key (`think<n>`) that
-	// survives the provisional→committed (seq null → seq N) transition, so the
-	// collapse's open/close state is NOT lost when a turn seals. (App isolates
-	// these keys per conversation via {#key}.)
+	function formatMs(ms: number): string {
+		if (ms < 1000) return `${Math.round(ms)}ms`;
+		const s = ms / 1000;
+		return s < 60 ? `${s.toFixed(1)}s` : `${Math.floor(s / 60)}m${Math.round(s % 60)}s`;
+	}
+
 	const rows = $derived.by(() => {
 		let thinking = 0;
+		let stepIdx = 0;
 		return groups.map((group, i) => {
 			let key: string;
 			if (group.kind === "tool-batch") {
@@ -22,14 +33,17 @@
 			} else {
 				key = `p${i}`;
 			}
-			return { group, key };
+			const si = stepIdx;
+			if (group.kind === "tool-batch" || (group.kind === "single" && (group.chunk.chunk.type === "tool-call" || group.chunk.chunk.type === "tool-result"))) {
+				stepIdx++;
+			}
+			return { group, key, stepIdx: si };
 		});
 	});
 </script>
 
-{#snippet chunkRow(rendered: RenderedChunk)}
+{#snippet chunkRow(rendered: RenderedChunk, sIdx: number)}
 	{#if rendered.role === "user"}
-		<!-- User: a speech bubble, left-aligned -->
 		<div class="chat chat-start">
 			<div class="chat-bubble chat-bubble-primary">
 				{#if rendered.chunk.type === "text"}
@@ -38,9 +52,6 @@
 			</div>
 		</div>
 	{:else if rendered.chunk.type === "thinking"}
-		<!-- Thinking: a visible bubble (like tool cards), holding a checkbox collapse
-		     (no arrow icon, smooth open/close). Title reads "Thinking" + loading dots
-		     while generating, then "Thoughts" with no dots once complete. -->
 		<div class="chat chat-start [&>.chat-bubble]:max-w-5xl [&>.chat-bubble]:p-0">
 			<div class="chat-bubble w-full bg-transparent">
 				<div class="collapse w-full rounded-box bg-base-200 text-sm">
@@ -58,14 +69,18 @@
 			</div>
 		</div>
 	{:else if rendered.chunk.type === "tool-call" || rendered.chunk.type === "tool-result"}
-		<!-- Single tool call/result: a regular (non-speech) card. Nested in the
-		     chat-start grid via a transparent, padding-stripped chat-bubble shim so
-		     the card inherits the same left offset as the bubble bodies. -->
+		{@const step = currentTurnId ? stepMetrics(telemetry, currentTurnId, sIdx) : undefined}
+		{@const toolDur = step?.toolDurationMs}
 		<div class="chat chat-start [&>.chat-bubble]:max-w-full [&>.chat-bubble]:p-0">
 			<div class="chat-bubble bg-transparent">
 				{#if rendered.chunk.type === "tool-call"}
 					<div class="w-fit max-w-full rounded-box bg-base-200 p-3 text-sm">
-						<strong>{rendered.chunk.toolName}</strong>
+						<div class="flex items-center gap-2">
+							<strong>{rendered.chunk.toolName}</strong>
+							{#if toolDur !== undefined && toolDur > 0}
+								<span class="badge badge-ghost badge-xs ml-auto">{formatMs(toolDur)}</span>
+							{/if}
+						</div>
 						<pre class="text-xs mt-1">{JSON.stringify(rendered.chunk.input, null, 2)}</pre>
 					</div>
 				{:else}
@@ -73,19 +88,43 @@
 						class="w-fit max-w-full rounded-box bg-base-200 p-3 text-sm"
 						class:text-error={rendered.chunk.isError}
 					>
-						<strong>{rendered.chunk.toolName}</strong>
+						<div class="flex items-center gap-2">
+							<strong>{rendered.chunk.toolName}</strong>
+							{#if toolDur !== undefined && toolDur > 0}
+								<span class="badge badge-ghost badge-xs ml-auto">{formatMs(toolDur)}</span>
+							{/if}
+						</div>
 						<pre class="text-xs mt-1">{rendered.chunk.content}</pre>
 					</div>
 				{/if}
 			</div>
 		</div>
 	{:else}
-		<!-- Assistant text / system / error: an INVISIBLE speech bubble — same
-		     chat-start grid as the user bubble, so it inherits identical left spacing. -->
+		{@const step = currentTurnId ? stepMetrics(telemetry, currentTurnId, sIdx) : undefined}
+		{@const tps = step ? stepTps(step) : undefined}
 		<div class="chat chat-start [&>.chat-bubble]:max-w-5xl">
 			<div class="chat-bubble w-full bg-transparent">
 				{#if rendered.chunk.type === "text"}
-					<p>{rendered.chunk.text}</p>
+					<ul class="list rounded-box text-sm">
+						<li class="list-row">
+							<p>{rendered.chunk.text}</p>
+						</li>
+						{#if step && (step.genTotalMs !== undefined || tps !== undefined || step.usage?.outputTokens !== undefined)}
+							<li class="list-row">
+								{#if step.genTotalMs !== undefined}
+									<span class="badge badge-ghost badge-xs">{formatMs(step.genTotalMs)}</span>
+								{/if}
+								<span>·</span>
+								{#if tps !== undefined}
+									<span class="badge badge-ghost badge-xs">{Math.round(tps)} t/s</span>
+								{/if}
+								<span>·</span>
+								{#if step.usage?.outputTokens !== undefined}
+									<span class="badge badge-ghost badge-xs">{step.usage.outputTokens} tok</span>
+								{/if}
+							</li>
+						{/if}
+					</ul>
 				{:else if rendered.chunk.type === "error"}
 					<div class="text-error" role="alert">
 						{rendered.chunk.message}
@@ -102,20 +141,24 @@
 {/snippet}
 
 <div class="flex flex-col gap-2 p-4 pl-6" role="log" aria-live="polite">
-	{#each rows as { group, key } (key)}
+	{#each rows as { group, key, stepIdx } (key)}
 		{#if group.kind === "single"}
-			{@render chunkRow(group.chunk)}
+			{@render chunkRow(group.chunk, stepIdx)}
 		{:else}
-			<!-- Batched tool calls (one step): a single bubble holding a DaisyUI list,
-			     one row per call paired with its result. Same chat-start grid shim as
-			     the single tool card so it lines up with the other messages. -->
+			{@const step = currentTurnId ? stepMetrics(telemetry, currentTurnId, stepIdx) : undefined}
+			{@const toolDur = step?.toolDurationMs}
 			<div class="chat chat-start [&>.chat-bubble]:max-w-full [&>.chat-bubble]:p-0">
 				<div class="chat-bubble bg-transparent">
 					<ul class="list w-fit max-w-full rounded-box bg-base-200 text-sm">
 						{#each group.entries as entry (entry.call.toolCallId)}
 							<li class="list-row">
 								<div>
-									<strong>{entry.call.toolName}</strong>
+									<div class="flex items-center gap-2">
+										<strong>{entry.call.toolName}</strong>
+										{#if toolDur !== undefined && toolDur > 0}
+											<span class="badge badge-ghost badge-xs ml-auto">{formatMs(toolDur)}</span>
+										{/if}
+									</div>
 									<pre class="text-xs mt-1">{JSON.stringify(entry.call.input, null, 2)}</pre>
 									{#if entry.result}
 										<pre
diff --git a/src/features/chat/ui/TurnSummary.svelte b/src/features/chat/ui/TurnSummary.svelte
new file mode 100644
index 0000000..eedb0cc
--- /dev/null
+++ b/src/features/chat/ui/TurnSummary.svelte
@@ -0,0 +1,75 @@
+<script lang="ts">
+	import type { TelemetryState } from "../../../core/telemetry";
+	import {
+		stepCount,
+		totalInputTokens,
+		totalOutputTokens,
+		turnMetrics,
+		turnTps,
+	} from "../../../core/telemetry";
+
+	interface Props {
+		telemetry: TelemetryState;
+		turnId: string | null;
+	}
+
+	let { telemetry, turnId }: Props = $props();
+
+	function formatMs(ms: number): string {
+		if (ms < 1000) return `${Math.round(ms)}ms`;
+		const s = ms / 1000;
+		return s < 60 ? `${s.toFixed(1)}s` : `${Math.floor(s / 60)}m${Math.round(s % 60)}s`;
+	}
+
+	const stats = $derived.by(() => {
+		if (turnId === null) return null;
+		const metrics = turnMetrics(telemetry, turnId);
+		if (metrics === undefined) return null;
+
+		const items: { label: string; value: string }[] = [];
+
+		if (metrics.wallMs !== undefined) {
+			items.push({ label: "Turn", value: formatMs(metrics.wallMs) });
+		}
+
+		const outTokens = totalOutputTokens(telemetry, turnId);
+		const inTokens = totalInputTokens(telemetry, turnId);
+		if (outTokens !== undefined || inTokens !== undefined) {
+			const total = (outTokens ?? 0) + (inTokens ?? 0);
+			items.push({ label: "Tokens", value: total.toLocaleString() });
+		}
+		if (outTokens !== undefined) {
+			items.push({ label: "Output", value: outTokens.toLocaleString() });
+		}
+		if (inTokens !== undefined) {
+			items.push({ label: "Input", value: inTokens.toLocaleString() });
+		}
+
+		const count = stepCount(telemetry, turnId);
+		if (count > 0) {
+			items.push({ label: "Steps", value: String(count) });
+		}
+
+		const tps = turnTps(telemetry, turnId);
+		if (tps !== undefined) {
+			items.push({ label: "TPS", value: `${Math.round(tps)} t/s` });
+		}
+
+		return items;
+	});
+</script>
+
+{#if stats !== null}
+	<div class="chat chat-start [&>.chat-bubble]:max-w-5xl">
+		<div class="chat-bubble w-full bg-transparent">
+			<div class="stats stats-vertical lg:stats-horizontal">
+				{#each stats as stat}
+					<div class="stat">
+						<div class="stat-title">{stat.label}</div>
+						<div class="stat-value text-sm">{stat.value}</div>
+					</div>
+				{/each}
+			</div>
+		</div>
+	</div>
+{/if}