Address review: re-check a failed resolution before declining an agent target

A page's element can be momentarily absent (a route still rendering, an
HMR commit mid-swap), so a failed resolution is not that page's final
word. The overlay now re-checks at 300, 700, and 1500 ms, claims the moment
the element mounts (the server already drops the stale report on an
eligible claim), and reports only the last miss. A genuine no_match now
takes about two seconds instead of tens of milliseconds, well inside the
server's hold.

Also normalizes a path separator in the new hook unit test, which failed
on rust-windows because the audit's file path carries backslashes there.

AI-assisted: implemented and tested with Claude Code under maintainer
direction.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/hook/tests/hook_tests.rs

@@ -2279,5 +2279,6 @@ fn run_hook_stands_down_for_the_whole_edit_when_the_primary_carries_live_markers
     let skipped = hook::run_hook(&r, &edit_event(&cwd, &wrapped, "s2"));
     assert_eq!(skipped.stdout, "", "nothing is emitted while the edited file is in a live session");
     assert_eq!(skipped.audit["skipped"], json!("live-preview"));
-    assert!(audit_str(&skipped.audit, "file").unwrap_or("").ends_with("src/App.jsx"), "the audit names the edited file, not the companion");
+    let audited = audit_str(&skipped.audit, "file").unwrap_or("").replace('\\', "/");
+    assert!(audited.ends_with("src/App.jsx"), "the audit names the edited file, not the companion: {audited}");
 }

skill/scripts/live-browser.js

@@ -7291,13 +7291,36 @@
   // another page has. The server prefers a busy report (a tab that could
   // serve later) over these, and returns the resolution verdict only when
   // no connected page can serve.
+  //
+  // An element can be momentarily absent (a route still rendering, an HMR
+  // commit mid-swap), so a failed resolution is not this page's final word:
+  // it is re-checked a few times over about two seconds, claiming the
+  // moment the element mounts, and only the last miss is reported. The
+  // server's timeout still bounds the whole exchange.
+  const AGENT_TARGET_RESOLVE_RETRY_MS = [300, 700, 1500];
+
   function declineAgentTargetUnresolvable(msg) {
     const probe = resolveAgentTargetElement(msg);
     if (!probe.error) return false;
-    claimAgentTarget(msg.targetId, { eligible: false, state, reason: 'no_match', result: probe.error });
+    retryAgentTargetResolution(msg, 0, probe.error);
     return true;
   }
 
+  function retryAgentTargetResolution(msg, attempt, lastError) {
+    if (attempt >= AGENT_TARGET_RESOLVE_RETRY_MS.length) {
+      claimAgentTarget(msg.targetId, { eligible: false, state, reason: 'no_match', result: lastError });
+      return;
+    }
+    setTimeout(() => {
+      if (agentTargetOverlayGone()) return;
+      const busy = agentTargetBusyReason();
+      if (busy) { declineAgentTargetBusy(msg, busy); return; }
+      const probe = resolveAgentTargetElement(msg);
+      if (!probe.error) { claimAndActOnAgentTarget(msg); return; }
+      retryAgentTargetResolution(msg, attempt + 1, probe.error);
+    }, AGENT_TARGET_RESOLVE_RETRY_MS[attempt]);
+  }
+
   function handleAgentTarget(msg) {
     if (!msg || typeof msg.targetId !== 'string') return;
     if (agentTargetsSeen.includes(msg.targetId)) return;

tests/live-browser-source.test.mjs

@@ -866,8 +866,13 @@ describe('live-browser source contracts', () => {
     );
     assert.match(
       SOURCE,
-      /function declineAgentTargetUnresolvable\(msg\) \{[\s\S]{0,200}?resolveAgentTargetElement\(msg\)[\s\S]{0,200}?reason: 'no_match', result: probe\.error/,
-      'the decline carries the resolution verdict for the server to return when no page can serve',
+      /function declineAgentTargetUnresolvable\(msg\) \{[\s\S]{0,200}?resolveAgentTargetElement\(msg\)[\s\S]{0,120}?retryAgentTargetResolution\(msg, 0, probe\.error\)/,
+      'a failed resolution is re-checked before it becomes this page\'s word',
+    );
+    assert.match(
+      SOURCE,
+      /function retryAgentTargetResolution\(msg, attempt, lastError\) \{[\s\S]{0,200}?reason: 'no_match', result: lastError[\s\S]{0,600}?if \(!probe\.error\) \{ claimAndActOnAgentTarget\(msg\); return; \}/,
+      'the page claims the moment the element mounts, and reports only the last miss',
     );
     // The per-origin session cache must not let a tab on another page of
     // the app resume this page's session (it would sit in GENERATING for a
@@ -885,8 +890,8 @@ describe('live-browser source contracts', () => {
     );
     assert.equal(
       (SOURCE.match(/claimAndActOnAgentTarget\(msg\)/g) || []).length,
-      4,
-      'the first claim and the busy-to-idle re-claim must share the rescue path (definition, two call sites, the retry)',
+      5,
+      'the first claim, the busy-to-idle re-claim, and the resolution re-check must share the rescue path (definition, three call sites, the retry)',
     );
   });