fix(hosting): propagate preview token in nav links + enrich pages with scraped content

Preview token propagation:
- JavaScript in storefront base.html appends _preview query param to
  all internal links when in preview mode, so clicking nav items
  (Services, Contact, etc.) preserves the preview bypass

Scraped content enrichment:
- POC builder now appends first 5 scraped paragraphs to about/services/
  projects pages, so the POC shows actual content from the prospect's
  site instead of just generic template text
- Extracts tagline from second scraped heading

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/hosting/services/poc_builder_service.py

@@ -147,8 +147,16 @@ class PocBuilderService:
                     context["meta_description"] = scraped["meta_description"]
                 if scraped.get("paragraphs"):
                     context["about_paragraph"] = scraped["paragraphs"][0]
-                if scraped.get("headings") and not prospect.business_name:
-                    context["business_name"] = scraped["headings"][0]
+                    # Build rich content from scraped paragraphs for page bodies
+                    context["scraped_paragraphs_html"] = "\n".join(
+                        f"<p>{p}</p>" for p in scraped["paragraphs"][:5]
+                    )
+                if scraped.get("headings"):
+                    if not prospect.business_name:
+                        context["business_name"] = scraped["headings"][0]
+                    # Use second heading as tagline if available
+                    if len(scraped["headings"]) > 1:
+                        context["tagline"] = scraped["headings"][1]
             except (json.JSONDecodeError, KeyError):
                 pass
 
@@ -203,6 +211,16 @@ class PocBuilderService:
             if content_translations and not content:
                 content = next(iter(content_translations.values()), "")
 
+            # Enrich with scraped paragraphs (append to template content)
+            scraped_html = context.get("scraped_paragraphs_html", "")
+            if scraped_html and slug in ("about", "services", "projects"):
+                content = content + "\n" + scraped_html if content else scraped_html
+                if content_translations:
+                    for lang_code in content_translations:
+                        content_translations[lang_code] = (
+                            content_translations[lang_code] + "\n" + scraped_html
+                        )
+
             page = ContentPage(
                 platform_id=platform_id,
                 store_id=store_id,