chore(telemetry): resolve loop crash caused by Temporal Dead Zone hoisting and fix conversational budget mapping

vibn-frontend/app/api/chat/route.ts

@@ -830,6 +830,66 @@ export async function POST(request: Request) {
       function emit(chunk: object) {
         if (streamClosed) return;
         try {
+          if (
+            "type" in chunk &&
+            chunk.type !== "ping" &&
+            chunk.type !== "turn_start"
+          ) {
+            if (chunk.type === "text" && "text" in chunk) {
+              assistantTimeline.push({ kind: "text", text: chunk.text });
+            } else if (chunk.type === "thinking" && "text" in chunk) {
+              assistantTimeline.push({ kind: "thought", text: chunk.text });
+            } else if (chunk.type === "tool_start" && "name" in chunk) {
+              assistantTimeline.push({
+                kind: "tool",
+                name: chunk.name,
+                status: "running",
+              });
+            } else if (
+              chunk.type === "tool_result" &&
+              "name" in chunk &&
+              "result" in chunk
+            ) {
+              const lastRunning = [...assistantTimeline]
+                .reverse()
+                .find(
+                  (t) =>
+                    t.kind === "tool" &&
+                    t.name === chunk.name &&
+                    t.status === "running",
+                );
+              if (lastRunning) {
+                lastRunning.status = "done";
+                lastRunning.result = chunk.result;
+                // Quick check if result indicates error
+                try {
+                  const p = JSON.parse(chunk.result as string);
+                  if (p && p.ok === false) lastRunning.status = "error";
+                } catch {}
+              }
+            } else if (
+              chunk.type === "phase" &&
+              "phase" in chunk &&
+              "label" in chunk
+            ) {
+              assistantTimeline.push({
+                kind: "phase",
+                phase: chunk.phase,
+                label: chunk.label,
+              });
+            } else if (
+              chunk.type === "checkpoint" &&
+              "goal" in chunk &&
+              "findings" in chunk
+            ) {
+              assistantTimeline.push({
+                kind: "checkpoint",
+                goal: chunk.goal,
+                findings: chunk.findings,
+              });
+            }
+          }
+
           controller.enqueue(
             encoder.encode(`data: ${JSON.stringify(chunk)}\n\n`),
           );
@@ -869,6 +929,7 @@ export async function POST(request: Request) {
       // restores the segmentation on reload.
       const assistantTextSegments: string[] = [];
       const assistantToolCalls: ToolCall[] = [];
+      const assistantTimeline: any[] = [];
       let aborted = clientSignal.aborted;
       const onAbort = () => {
         aborted = true;
@@ -1339,6 +1400,7 @@ export async function POST(request: Request) {
 
         const finalMsg: ChatMessage & {
           textSegments?: string[];
+          timeline?: any[];
           _rawToolResults?: Array<{
             name: string;
             args: Record<string, unknown>;
@@ -1356,6 +1418,7 @@ export async function POST(request: Request) {
                 ),
               )
             : undefined,
+          timeline: assistantTimeline.length ? assistantTimeline : undefined,
           _rawToolResults: assistantToolCalls.length ? [] : undefined,
         };