diff --git a/php-transformer/src/ArtifactCompiler/ArtifactCompiler.php b/php-transformer/src/ArtifactCompiler/ArtifactCompiler.php
index 9817f4ee..75f51073 100644
--- a/php-transformer/src/ArtifactCompiler/ArtifactCompiler.php
+++ b/php-transformer/src/ArtifactCompiler/ArtifactCompiler.php
@@ -2012,7 +2012,10 @@ private function compiledSiteReport(array $artifact, string $entryPath, array $d
                 $shellArtifact['slug'] = 'entry-' . $slug;
             }
             $partSlugs[(string) $shellArtifact['slug']] = true;
-            if ( is_string($shellArtifact['inner_block_markup'] ?? null) ) {
+            if ( is_string($shellArtifact['template_part_block_markup'] ?? null) ) {
+                $shellArtifact['block_markup'] = $shellArtifact['template_part_block_markup'];
+                unset($shellArtifact['template_part_block_markup'], $shellArtifact['inner_block_markup']);
+            } elseif ( is_string($shellArtifact['inner_block_markup'] ?? null) ) {
                 $shellArtifact['block_markup'] = $shellArtifact['inner_block_markup'];
                 unset($shellArtifact['inner_block_markup']);
             }
diff --git a/php-transformer/src/HtmlToBlocks/HtmlTransformer.php b/php-transformer/src/HtmlToBlocks/HtmlTransformer.php
index b5ec4f65..f1ecb3ee 100644
--- a/php-transformer/src/HtmlToBlocks/HtmlTransformer.php
+++ b/php-transformer/src/HtmlToBlocks/HtmlTransformer.php
@@ -662,6 +662,11 @@ private function globalShellArtifacts(DOMElement $body, string $source, bool $re
             // landmark around an independently converted landmark block.
             $blocks = array($this->createBlock('core/group', $wrapperAttrs, $blocks, $child));
             $markup = $this->runtime->serializeBlocks($blocks);
+            $templatePartAttrs = $wrapperAttrs;
+            unset($templatePartAttrs['tagName']);
+            $templatePartMarkup = array() === $templatePartAttrs
+                ? $innerMarkup
+                : $this->runtime->serializeBlocks(array($this->createBlock('core/group', $templatePartAttrs, $blocks[0]['innerBlocks'] ?? array())));
             if ( '' === trim($markup) ) {
                 continue;
             }
@@ -673,6 +678,7 @@ private function globalShellArtifacts(DOMElement $body, string $source, bool $re
                 'body_format' => 'blocks',
                 'block_markup' => $markup,
                 'inner_block_markup' => $innerMarkup,
+                'template_part_block_markup' => $templatePartMarkup,
                 'source_selector' => strtolower($child->tagName),
                 'source_classes' => $this->shellSourceClasses($child),
                 'source_hash' => hash('sha256', $this->outerHtml($child)),
diff --git a/php-transformer/src/WordPressSitePlan/WordPressSitePlan.php b/php-transformer/src/WordPressSitePlan/WordPressSitePlan.php
index 81b76787..60a5d768 100644
--- a/php-transformer/src/WordPressSitePlan/WordPressSitePlan.php
+++ b/php-transformer/src/WordPressSitePlan/WordPressSitePlan.php
@@ -247,7 +247,8 @@ private function shellCandidates(array $document, AssetReferenceCanonicalizer $r
             $classes = array_values(array_filter($candidate['source_classes'] ?? array(), 'is_string'));
             sort($classes, SORT_STRING);
             $innerMarkup = is_string($candidate['inner_block_markup'] ?? null) ? $this->routeLinks($references->content($candidate['inner_block_markup'], self::value($document, 'source_path')), self::value($document, 'source_path'), $routes) : $markup;
-            $candidates[] = array('area' => $candidate['area'], 'markup' => $markup, 'inner_markup' => $innerMarkup, 'classes' => $classes);
+            $templatePartMarkup = is_string($candidate['template_part_block_markup'] ?? null) ? $this->routeLinks($references->content($candidate['template_part_block_markup'], self::value($document, 'source_path')), self::value($document, 'source_path'), $routes) : $innerMarkup;
+            $candidates[] = array('area' => $candidate['area'], 'markup' => $markup, 'inner_markup' => $innerMarkup, 'template_part_markup' => $templatePartMarkup, 'classes' => $classes);
         }
         return $candidates;
     }
@@ -317,7 +318,7 @@ private function sharedShells(array $pages, array $reservedSlugs = array(), arra
             $sourcePath = $singlePage ? $pages[array_key_first($applicable)]['source_path'] : 'wordpress-site-plan/shared/' . $area;
             $placement = $singlePage ? 'entry_shell' : 'shared_shell';
             $templateSlugs = $singlePage ? array('front-page') : array('index', 'page', 'front-page');
-            $partMarkup = $first['markup'];
+            $partMarkup = $first['template_part_markup'];
             $parts[] = array('source_path' => $sourcePath . '#' . $area, 'slug' => $area, 'title' => ucfirst($area), 'post_type' => 'wp_template_part', 'parent_source_path' => '', 'entrypoint' => false, 'area' => $area, 'placement' => array('kind' => $placement, 'source_path' => $sourcePath, 'template_slugs' => $templateSlugs), 'canonical_block_markup' => $partMarkup, 'metadata' => array(), 'document_metadata' => array('source_context' => array('source_path' => $sourcePath . '#' . $area, 'kind' => 'template_part'), 'title' => ucfirst($area), 'title_declaration' => array('order' => 0, 'placement' => 'head'), 'meta' => array(), 'links' => array(), 'scripts' => array()), 'provenance' => array('shell_identity' => $identity), 'reconciliation_identity' => self::identity('template-part', $sourcePath . '#' . $area, 'parts/' . $area . '.html'), 'content_hash' => self::contentHash($partMarkup));
             $diagnostics[] = array('code' => $singlePage ? 'wordpress_site_plan_shell_entry_extracted' : 'wordpress_site_plan_shell_extracted', 'severity' => 'info', 'message' => $singlePage ? "Extracted the entry {$area} shell for the front-page template." : "Extracted one semantically equivalent {$area} shell for all pages.", 'area' => $area, 'page_count' => count($applicable));
         }
@@ -491,7 +492,7 @@ private function templates(array $pages, array $parts): array
         $markup = static function (string $templateSlug) use ($bound): string {
             $before = ''; $after = '';
             foreach ($bound as $part) if (in_array($templateSlug, $part['placement']['template_slugs'] ?? array(), true)) {
-                $reference = '<!-- wp:template-part {"slug":"' . $part['slug'] . '","area":"' . $part['area'] . '"} /-->' . "\n";
+                $reference = '<!-- wp:template-part {"slug":"' . $part['slug'] . '","area":"' . $part['area'] . '","tagName":"' . $part['area'] . '"} /-->' . "\n";
                 if ('footer' === $part['area']) $after .= $reference; else $before .= $reference;
             }
             return $before . '<!-- wp:post-content /-->' . "\n" . $after;
diff --git a/php-transformer/tests/contract/run.php b/php-transformer/tests/contract/run.php
index 205f8640..56eb0a20 100644
--- a/php-transformer/tests/contract/run.php
+++ b/php-transformer/tests/contract/run.php
@@ -2140,6 +2140,7 @@ public function match(DOMElement $element, PatternContext $context): ?array
 $canonicalEntryPage = array_values(array_filter($canonicalShellPlan['pages'] ?? array(), static fn (array $page): bool => 'index.html' === ($page['source_path'] ?? '')))[0] ?? array();
 $assert(! str_contains((string) ($canonicalEntryPage['canonical_block_markup'] ?? ''), 'Get started') && str_contains((string) ($canonicalHeaderPart['canonical_block_markup'] ?? ''), 'Get started'), 'canonical entry header is projected only to its shell part, without duplicate post-content chrome');
 $assert(str_contains((string) ($canonicalFooterPart['canonical_block_markup'] ?? ''), 'Global footer'), 'canonical entry footer part preserves global footer content');
+$assert(! str_contains((string) ($canonicalHeaderPart['canonical_block_markup'] ?? ''), '<header') && ! str_contains((string) ($canonicalFooterPart['canonical_block_markup'] ?? ''), '<footer'), 'canonical shell parts rely on their semantic template-part references instead of nesting duplicate landmarks');
 $assert(2 === count(array_filter($canonicalShellPlan['writes'] ?? array(), static fn (array $write): bool => 'theme_template_part' === ($write['kind'] ?? ''))), 'WordPress site plan exposes canonical entry header and footer writes');
 
 $runtimeDependencySite = $compiler->compile(
diff --git a/php-transformer/tests/contract/shared-shell-plan.php b/php-transformer/tests/contract/shared-shell-plan.php
index 9f452349..574d9d99 100644
--- a/php-transformer/tests/contract/shared-shell-plan.php
+++ b/php-transformer/tests/contract/shared-shell-plan.php
@@ -42,15 +42,17 @@
 $nearPages = $pages($nearMatch);
 $assert(str_contains($nearPages['index.html']['canonical_block_markup'] ?? '', 'Home') && str_contains($nearPages['about.html']['canonical_block_markup'] ?? '', 'Contact us') && !array_filter($nearMatch['template_parts'], static fn(array $part): bool => 'header' === ($part['area'] ?? null)), 'Route-specific header actions are retained as a near-match instead of being deduplicated.');
 
-$singleResult = (new ArtifactCompiler())->compile(array('entrypoint' => 'index.html', 'files' => array('index.html' => '<header class="solo"><p>Solo</p></header><main>Home</main><footer>Solo footer</footer>')))->toArray();
+$singleResult = (new ArtifactCompiler())->compile(array('entrypoint' => 'index.html', 'files' => array('index.html' => '<header id="solo-shell" class="solo" style="border-top:2px solid #111"><p>Solo</p></header><main>Home</main><footer>Solo footer</footer>')))->toArray();
 $single = $singleResult['source_reports']['wordpress_site_plan'];
 $singleWrites = $writes($single);
-$assert(2 === count(array_filter($single['template_parts'], static fn(array $part): bool => 'entry_shell' === ($part['placement']['kind'] ?? null))) && str_contains($singleWrites['templates/front-page.html']['payload']['data'], '"slug":"header"') && !str_contains($singleWrites['templates/page.html']['payload']['data'], '"slug":"header"') && !str_contains($singleWrites['templates/index.html']['payload']['data'], '"slug":"header"'), 'A single-page artifact retains entry-shell behavior and binds chrome only to front-page.');
+$assert(2 === count(array_filter($single['template_parts'], static fn(array $part): bool => 'entry_shell' === ($part['placement']['kind'] ?? null))) && str_contains($singleWrites['templates/front-page.html']['payload']['data'], '"slug":"header","area":"header","tagName":"header"') && str_contains($singleWrites['templates/front-page.html']['payload']['data'], '"slug":"footer","area":"footer","tagName":"footer"') && !str_contains($singleWrites['templates/page.html']['payload']['data'], '"slug":"header"') && !str_contains($singleWrites['templates/index.html']['payload']['data'], '"slug":"header"'), 'A single-page artifact binds semantic entry-shell template parts only to front-page.');
 $singleHeader = array_values(array_filter($single['template_parts'], static fn(array $part): bool => 'header' === ($part['area'] ?? null)))[0] ?? array();
-$assert(str_contains($singleHeader['canonical_block_markup'] ?? '', '"tagName":"header"') && str_contains($singleHeader['canonical_block_markup'] ?? '', 'solo') && str_contains($singleHeader['canonical_block_markup'] ?? '', 'Solo') && !str_contains($pages($single)['index.html']['canonical_block_markup'] ?? '', 'Solo</p>'), 'Single-page entry chrome preserves its semantic landmark and source presentation while removing it from post content.');
+$assert(!str_contains($singleHeader['canonical_block_markup'] ?? '', '"tagName":"header"') && !str_contains($singleHeader['canonical_block_markup'] ?? '', '<header') && str_contains($singleHeader['canonical_block_markup'] ?? '', '"className":"solo"') && str_contains($singleHeader['canonical_block_markup'] ?? '', '"anchor":"solo-shell"') && str_contains($singleHeader['canonical_block_markup'] ?? '', 'border-top:2px solid #111') && str_contains($singleHeader['canonical_block_markup'] ?? '', 'Solo') && !str_contains($pages($single)['index.html']['canonical_block_markup'] ?? '', 'Solo</p>'), 'Single-page entry chrome preserves source presentation without nesting a landmark inside the semantic template-part wrapper.');
 $compiledHeader = array_values(array_filter($singleResult['source_reports']['compiled_site']['template_parts'] ?? array(), static fn(array $part): bool => 'header' === ($part['area'] ?? null)))[0] ?? array();
 $compiledPage = $singleResult['source_reports']['compiled_site']['pages'][0] ?? array();
-$assert('entry_shell' === ($compiledHeader['placement']['kind'] ?? null) && !str_contains($compiledHeader['block_markup'] ?? '', '"tagName":"header"') && str_contains($compiledHeader['block_markup'] ?? '', 'Solo') && !str_contains($compiledPage['block_markup'] ?? '', 'Solo</p>'), 'The compiled-site compatibility report retains its established single-page entry shell projection without duplicate page chrome.');
+$assert('entry_shell' === ($compiledHeader['placement']['kind'] ?? null) && !str_contains($compiledHeader['block_markup'] ?? '', '"tagName":"header"') && !str_contains($compiledHeader['block_markup'] ?? '', '<header') && str_contains($compiledHeader['block_markup'] ?? '', '"className":"solo"') && str_contains($compiledHeader['block_markup'] ?? '', '"anchor":"solo-shell"') && str_contains($compiledHeader['block_markup'] ?? '', 'border-top:2px solid #111') && str_contains($compiledHeader['block_markup'] ?? '', 'Solo') && !str_contains($compiledPage['block_markup'] ?? '', 'Solo</p>'), 'The compiled-site compatibility report retains source presentation on a non-landmark wrapper without duplicate page chrome.');
+$materializedHeader = array_values(array_filter($singleResult['source_reports']['materialization_plan']['template_part_writes'] ?? array(), static fn(array $write): bool => 'header' === ($write['area'] ?? null)))[0] ?? array();
+$assert(str_contains($materializedHeader['content'] ?? '', '"className":"solo"') && str_contains($materializedHeader['content'] ?? '', '"anchor":"solo-shell"') && str_contains($materializedHeader['content'] ?? '', 'border-top:2px solid #111') && str_contains($materializedHeader['content'] ?? '', 'Solo') && !str_contains($materializedHeader['content'] ?? '', '"tagName":"header"') && !str_contains($materializedHeader['content'] ?? '', '<header'), 'The v1 materialization projection retains source presentation without nesting a header landmark inside the template-part wrapper.');
 
 $incomplete = (new ArtifactCompiler())->compile(array('entrypoint' => 'index.html', 'files' => array('index.html' => '<header>Shared</header><main>Home</main>', 'about.html' => '<header>Shared</header><main>About</main>', 'contact.html' => '<main>Contact</main>')))->toArray()['source_reports']['wordpress_site_plan'];
 $multiple = (new ArtifactCompiler())->compile(array('entrypoint' => 'index.html', 'files' => array('index.html' => '<header>One</header><header>Two</header><main>Home</main>', 'about.html' => '<header>One</header><header>Two</header><main>About</main>')))->toArray()['source_reports']['wordpress_site_plan'];