Fix product slug: extract from URL path instead of g.post_slug

App-level preprocessor pops slug then page_slug into g.post_slug,
overwriting the product slug with the page slug ("market"). Extract
the product slug directly from the request path after "/product/".

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

bp/product/routes.py

@@ -25,9 +25,17 @@ def register():
     bp = Blueprint("product", __name__, url_prefix="/product/<slug>")
     @bp.url_value_preprocessor
     def pull_blog(endpoint, values):
-      # App-level preprocessor pops "slug" into g.post_slug before this runs,
-      # so values.get("slug") is None. Fall back to g.post_slug.
-      g.product_slug = values.get("slug") or getattr(g, "post_slug", None)
+      # App-level preprocessor pops both "slug" and "page_slug" into g.post_slug,
+      # with page_slug overwriting slug. We need the original product slug which
+      # the app preprocessor popped first — but it's gone. Instead, extract the
+      # product slug from the request path: .../product/<slug>/...
+      from quart import request as req
+      parts = req.path.rstrip("/").split("/")
+      try:
+          idx = parts.index("product")
+          g.product_slug = parts[idx + 1] if idx + 1 < len(parts) else None
+      except (ValueError, IndexError):
+          g.product_slug = None
 
     # ─────────────────────────────────────────────────────────────
     # BEFORE REQUEST: Slug or numeric ID resolver