fix(browser): Add MAX_PLAUSIBLE_INP_DURATION check to streamed INP span path

The standalone INP handler filters out unrealistically long INP values
(>60s) but the streamed span path was missing this sanity check.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: logaretm

packages/browser-utils/src/metrics/webVitalSpans.ts

@@ -22,6 +22,9 @@ import type { InstrumentationHandlerCallback } from './instrument';
 import { addClsInstrumentationHandler, addInpInstrumentationHandler, addLcpInstrumentationHandler } from './instrument';
 import { listenForWebVitalReportEvents, msToSec, supportsWebVital } from './utils';
 
+// Maximum plausible INP duration in seconds (matches standalone INP handler)
+const MAX_PLAUSIBLE_INP_DURATION = 60;
+
 interface WebVitalSpanOptions {
   name: string;
   op: string;
@@ -215,6 +218,11 @@ export function trackInpAsSpan(_client: Client): void {
       return;
     }
 
+    // Guard against unrealistically long INP values (matching standalone INP handler)
+    if (msToSec(metric.value) > MAX_PLAUSIBLE_INP_DURATION) {
+      return;
+    }
+
     const entry = metric.entries.find(e => e.duration === metric.value && INP_ENTRY_MAP[e.name]);
 
     if (!entry) {