Preserve experimental Live app-server workstream

Snapshot the current app-server implementation, shared Live optimizations, generated harness output, and in-progress site work before restoring polling as the primary runtime path.

Prepared with Codex assistance under maintainer direction.

tests/live-e2e/agent.mjs

@@ -1518,7 +1518,16 @@ async function publishSourceVariants({ tmp, wrapInfo, event, output }) {
   return published;
 }
 
-async function publishVariantProgress({ base, token, event, wrapInfo, arrivedVariants, signal }) {
+async function publishVariantProgress({
+  base,
+  token,
+  event,
+  wrapInfo,
+  arrivedVariants,
+  signal,
+  revision = 1,
+  publicationKind = 'variants',
+}) {
   const previewMode = wrapInfo.previewMode || 'source';
   await fetch(`${base}/events`, {
     method: 'POST',
@@ -1527,7 +1536,8 @@ async function publishVariantProgress({ base, token, event, wrapInfo, arrivedVar
       token,
       type: 'checkpoint',
       id: event.id,
-      revision: 1,
+      revision,
+      revisionDomain: 'publication',
       phase: 'cycling',
       reason: 'variants_progress',
       arrivedVariants,
@@ -1535,6 +1545,7 @@ async function publishVariantProgress({ base, token, event, wrapInfo, arrivedVar
       sourceFile: wrapInfo.sourceFile || wrapInfo.file,
       previewFile: wrapInfo.file,
       previewMode,
+      publicationKind,
     }),
     signal,
   });
@@ -1897,6 +1908,18 @@ export async function runAgentLoop({
           await spliceVariantsIntoWrapper({ tmp, wrapInfo, sessionId: event.id, output });
         }
         trace('agent.write.end', { id: event.id, file: wrapInfo.file });
+        if (progressive) {
+          await publishVariantProgress({
+            base,
+            token,
+            event,
+            wrapInfo,
+            arrivedVariants: output.variants.length,
+            signal,
+            revision: 2,
+            publicationKind: 'params',
+          });
+        }
         if (process.env.IMPECCABLE_E2E_DEBUG) {
           const post = await fs.readFile(path.join(tmp, wrapInfo.file), 'utf-8');
           log(`--- post-splice (variants written) ---\n${post}`);

tests/live-e2e/ui.mjs

@@ -432,7 +432,7 @@ export async function pickElement(page, selector, opts = {}) {
         const bar = query(barSel);
         const pick = query(pickSel);
         return {
-          liveState: document.documentElement.dataset.impeccableLiveState || null,
+          liveState: window.__IMPECCABLE_LIVE_STATE__ || null,
           target: target ? { tag: target.tagName, classes: target.className, rect: rect?.toJSON?.() || null } : null,
           hit: hit ? { tag: hit.tagName, classes: hit.className, text: (hit.textContent || '').slice(0, 80) } : null,
           pickActive: pick?.dataset.active || null,