fix(wechat): repair share preview on disk for sanitized delivery artifacts

Production WeChat delivery strips localPath from artifacts, so share-preview
auto-repair never wrote back to HTML. Resolve paths via publishDir +
relativePath, repair at materialize and delivery prep, and pass h5Root from
Portal so page.generate can patch missing meta before sending links.

Co-authored-by: Cursor <cursoragent@cursor.com>

wechat/handlers/page-generate.mjs

@@ -8,17 +8,25 @@ export function evaluatePageGenerateSendableArtifacts({
   confirmedArtifacts = [],
   repairContext = {},
 } = {}) {
-  const sendable = selectSendableHtmlArtifacts({ verifiedArtifacts, confirmedArtifacts });
-  const verified = sendable.filter((artifact) => verifyPageArtifactContent(artifact).ok);
+  const publishDir = String(repairContext.publishDir ?? '').trim();
+  const previewOptions = { publishDir };
+  const sendable = selectSendableHtmlArtifacts({
+    verifiedArtifacts,
+    confirmedArtifacts,
+    publishDir,
+  });
+  const verified = sendable.filter((artifact) =>
+    verifyPageArtifactContent(artifact, previewOptions).ok,
+  );
   const candidates = verified.length > 0 ? verified : sendable;
-  const ready = filterSharePreviewReadyArtifacts(candidates);
+  const ready = filterSharePreviewReadyArtifacts(candidates, previewOptions);
   if (ready.length > 0) return ready;
 
   const repaired = [];
   for (const artifact of candidates) {
-    if (!verifyPageArtifactContent(artifact).ok) continue;
+    if (!verifyPageArtifactContent(artifact, previewOptions).ok) continue;
     const result = repairArtifactSharePreview(artifact, repairContext);
-    if (result.ok && verifyArtifactSharePreview(artifact).ok) {
+    if (result.ok && verifyArtifactSharePreview(artifact, previewOptions).ok) {
       repaired.push(artifact);
     }
   }
@@ -42,8 +50,10 @@ export function resolvePageGenerateOutcome({
 }) {
   const context = {
     topic: String(topic || repairContext.topic || '').trim(),
+    publishDir: String(repairContext.publishDir ?? '').trim(),
     ...repairContext,
   };
+  const previewOptions = { publishDir: context.publishDir };
   const sendable = evaluatePageGenerateSendableArtifacts({
     verifiedArtifacts,
     confirmedArtifacts,
@@ -71,11 +81,21 @@ export function resolvePageGenerateOutcome({
   }
 
   const previewCandidates = filterSharePreviewReadyArtifacts(
-    selectSendableHtmlArtifacts({ verifiedArtifacts, confirmedArtifacts }),
+    selectSendableHtmlArtifacts({
+      verifiedArtifacts,
+      confirmedArtifacts,
+      publishDir: context.publishDir,
+    }),
+    previewOptions,
   );
   if (previewCandidates.length === 0 && confirmedArtifacts.length > 0) {
     const previewIssue = verifyArtifactSharePreview(
-      selectSendableHtmlArtifacts({ verifiedArtifacts, confirmedArtifacts })[0] ?? confirmedArtifacts[0],
+      selectSendableHtmlArtifacts({
+        verifiedArtifacts,
+        confirmedArtifacts,
+        publishDir: context.publishDir,
+      })[0] ?? confirmedArtifacts[0],
+      previewOptions,
     );
     return {
       action: 'fail',