From 40b2a8065344547a507b174488f60184721d1eb5 Mon Sep 17 00:00:00 2001
From: Paul Bakaus <paul.bakaus@gmail.com>
Date: Mon, 27 Jul 2026 16:11:52 -0700
Subject: [PATCH] fix: restrict server-session adoption to comparison phases

The CI-only astro accept hang: the carbonize source edit triggers a
framework reload, and on a slow runner the reloaded page rehydrated the
still-non-terminal carbonize_required session back into GENERATING,
stranding the bar over a decided comparison. Adoption now uses a
positive allowlist of comparison phases (generate_requested,
variants_ready, generating, cycling); accept/carbonize/steer/manual
phases are agent-side work and never adoptable. Regression guard pins
the allowlist.

This work was produced with AI assistance (Claude Code).

Co-Authored-By: Claude Code <noreply@anthropic.com>
---
 skill/scripts/live-browser.js          | 16 +++++++++++-----
 tests/live-browser-regression.test.mjs | 11 +++++++++--
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/skill/scripts/live-browser.js b/skill/scripts/live-browser.js
index 308b494bd..b95d8b5a8 100644
--- a/skill/scripts/live-browser.js
+++ b/skill/scripts/live-browser.js
@@ -8670,6 +8670,16 @@ void main() {
    * not evidence that it belongs to THIS page, and adopting it would hijack an
    * unrelated route.
    */
+  // Phases in which the user is (or should be) comparing variants. Only these
+  // are adoptable by a browser with no local record. Steer and manual-edit
+  // sessions have no wrapper to restore, and accept/carbonize phases are
+  // agent-side work: a reload mid-carbonize must not resurrect the bar over a
+  // page whose comparison is already decided (a slow-CI reload hit exactly
+  // that window and left the bar stranded after accept).
+  const ADOPTABLE_SESSION_PHASES = new Set([
+    'generate_requested', 'variants_ready', 'generating', 'cycling',
+  ]);
+
   function findAdoptableServerSession(activeSessions) {
     if (!Array.isArray(activeSessions)) return null;
     return activeSessions.find((session) => (
@@ -8679,12 +8689,8 @@ void main() {
       && session.pageUrl
       && pageMatchesCurrent(session.pageUrl)
       && (session.previewFile || session.sourceFile)
-      // Only variant comparisons are adoptable. A steer or manual-edit
-      // session is non-terminal and carries a sourceFile, but restoring it
-      // as a comparison hunts for a variant wrapper that never existed and
-      // wedges the bar before the user's next pick.
       && Number(session.expectedVariants) > 0
-      && !/^(steer|manual_edit)/.test(String(session.phase || ''))
+      && ADOPTABLE_SESSION_PHASES.has(String(session.phase || ''))
     )) || null;
   }
 
diff --git a/tests/live-browser-regression.test.mjs b/tests/live-browser-regression.test.mjs
index c46a9456f..4811f20c4 100644
--- a/tests/live-browser-regression.test.mjs
+++ b/tests/live-browser-regression.test.mjs
@@ -1357,8 +1357,15 @@ describe('live-browser.js regression guards', () => {
     );
     assert.match(
       SOURCE,
-      /function findAdoptableServerSession\([\s\S]{0,900}?\^\(steer\|manual_edit\)/,
-      'adoption must exclude steer and manual-edit phases',
+      /function findAdoptableServerSession\([\s\S]{0,900}?ADOPTABLE_SESSION_PHASES\.has\(String\(session\.phase/,
+      'adoption must be limited to the comparison-phase allowlist',
+    );
+    // Accept/carbonize phases are agent-side work; adopting them resurrects
+    // the bar over a decided comparison (the slow-CI astro accept hang).
+    assert.doesNotMatch(
+      SOURCE,
+      /ADOPTABLE_SESSION_PHASES = new Set\(\[[\s\S]{0,200}?(accept_requested|carbonize|steer|manual_edit)/,
+      'accept, carbonize, steer, and manual-edit phases must not be adoptable',
     );
   });