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/verify/share-preview.mjs

@@ -1,5 +1,6 @@
 import fs from 'node:fs';
 import { artifactFileExists } from './page-artifact.mjs';
+import { resolveArtifactLocalPath } from './page-artifact.mjs';
 import { hasPlatformBrandMarker } from '../../mindspace-page-tag.mjs';
 
 export { hasPlatformBrandMarker };
@@ -57,26 +58,30 @@ export function verifySharePreviewMeta(html) {
   return { ok: true, reason: null };
 }
 
-export function verifyArtifactSharePreview(artifact) {
-  if (!artifactFileExists(artifact)) {
-    return { ok: false, reason: 'missing_file' };
-  }
-  if (!String(artifact?.localPath ?? '').trim()) {
-    if (
-      typeof artifact?.sharePreview?.ok ===
-      'boolean'
-    ) {
-      return artifact.sharePreview;
+export function verifyArtifactSharePreview(artifact, { publishDir = '' } = {}) {
+  const localPath = resolveArtifactLocalPath(artifact, publishDir);
+  if (localPath) {
+    try {
+      if (fs.existsSync(localPath) && fs.statSync(localPath).isFile()) {
+        const content = fs.readFileSync(localPath, 'utf8');
+        return verifySharePreviewMeta(content);
+      }
+    } catch {
+      // Fall back to cached sharePreview metadata below.
     }
-    return {
-      ok: false,
-      reason: 'missing_share_preview_evaluation',
-    };
   }
-  const content = fs.readFileSync(artifact.localPath, 'utf8');
-  return verifySharePreviewMeta(content);
+  if (
+    typeof artifact?.sharePreview?.ok ===
+    'boolean'
+  ) {
+    return artifact.sharePreview;
+  }
+  return {
+    ok: false,
+    reason: 'missing_file',
+  };
 }
 
-export function filterSharePreviewReadyArtifacts(artifacts = []) {
-  return artifacts.filter((artifact) => verifyArtifactSharePreview(artifact).ok);
+export function filterSharePreviewReadyArtifacts(artifacts = [], options = {}) {
+  return artifacts.filter((artifact) => verifyArtifactSharePreview(artifact, options).ok);
 }