fix(web): tolerant polling, objectURL cleanup, throttled pointermove

- home/detail video pollers no longer clearInterval on a single transient error
  (give up only after 10 consecutive failures), matching the agent page
- agent page creates preview objectURLs inside useEffect so each has a matching
  revoke under strict-mode double-invocation
- login pointermove throttled via rAF and skipped on coarse pointers
- source-analysis.html: changelog entry for this hardening pass

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/app/agent/page.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import { useEffect, useMemo, useRef, useState } from "react"
+import { useEffect, useRef, useState } from "react"
 import {
   ArrowDownToLine,
   CheckCircle2,
@@ -73,8 +73,14 @@ export default function AgentPage() {
   const [error, setError] = useState("")
   const terminalRef = useRef<HTMLDivElement>(null)
 
-  const previews = useMemo(() => files.map((file) => ({ file, url: URL.createObjectURL(file) })), [files])
-  useEffect(() => () => previews.forEach((item) => URL.revokeObjectURL(item.url)), [previews])
+  // create object URLs inside the effect (not during render) so every URL has a
+  // matching revoke even under React strict-mode double-invocation
+  const [previews, setPreviews] = useState<{ file: File; url: string }[]>([])
+  useEffect(() => {
+    const next = files.map((file) => ({ file, url: URL.createObjectURL(file) }))
+    setPreviews(next)
+    return () => next.forEach((item) => URL.revokeObjectURL(item.url))
+  }, [files])
 
   useEffect(() => {
     fetch(`${API_BASE}/agent-runs?limit=8`, { cache: "no-store" })

web/app/detail/page.tsx

@@ -116,11 +116,16 @@ export default function DetailPage() {
 
   useEffect(() => {
     if (!job || !runningVideo) return
+    let failures = 0
     const timer = window.setInterval(async () => {
       try {
         setJob(await getJob(job.id))
+        failures = 0
       } catch {
-        window.clearInterval(timer)
+        // one transient 5xx / network blip must not freeze progress forever;
+        // only give up after sustained failures
+        failures += 1
+        if (failures >= 10) window.clearInterval(timer)
       }
     }, 2600)
     return () => window.clearInterval(timer)

web/app/login/page.tsx

@@ -61,15 +61,26 @@ export default function LoginPage() {
   }, [])
 
   useEffect(() => {
+    // skip touch / coarse pointers — the eye-follow effect is pointless there and
+    // would thrash state (and battery) on scroll-driven pointer events
+    if (typeof window !== "undefined" && window.matchMedia?.("(pointer: coarse)").matches) return
+    let frame = 0
     const onPointerMove = (event: PointerEvent) => {
-      const centerX = window.innerWidth / 2
-      const centerY = window.innerHeight / 2
-      const nextX = Math.max(-1, Math.min(1, (event.clientX - centerX) / centerX))
-      const nextY = Math.max(-1, Math.min(1, (event.clientY - centerY) / centerY))
-      setEyeOffset({ x: nextX * 8, y: nextY * 5.5 })
+      if (frame) return // coalesce to at most one state update per animation frame
+      frame = window.requestAnimationFrame(() => {
+        frame = 0
+        const centerX = window.innerWidth / 2
+        const centerY = window.innerHeight / 2
+        const nextX = Math.max(-1, Math.min(1, (event.clientX - centerX) / centerX))
+        const nextY = Math.max(-1, Math.min(1, (event.clientY - centerY) / centerY))
+        setEyeOffset({ x: nextX * 8, y: nextY * 5.5 })
+      })
     }
     window.addEventListener("pointermove", onPointerMove)
-    return () => window.removeEventListener("pointermove", onPointerMove)
+    return () => {
+      window.removeEventListener("pointermove", onPointerMove)
+      if (frame) window.cancelAnimationFrame(frame)
+    }
   }, [])
 
   const disabled = status === "loading" || status === "success"

web/app/page.tsx

@@ -191,11 +191,16 @@ export default function Home() {
 
   useEffect(() => {
     if (!job || !runningVideo) return
+    let failures = 0
     const timer = window.setInterval(async () => {
       try {
         setJob(await getJob(job.id))
+        failures = 0
       } catch {
-        window.clearInterval(timer)
+        // one transient 5xx / network blip must not freeze progress forever;
+        // only give up after sustained failures
+        failures += 1
+        if (failures >= 10) window.clearInterval(timer)
       }
     }, 2600)
     return () => window.clearInterval(timer)