Add market admin CRUD: list, create, and delete marketplaces

Replaces placeholder "Market admin" text with a functional admin panel
that lists marketplaces for a page and supports create/delete via sx,
mirroring the events calendar admin pattern.

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

market/bp/page_admin/routes.py

@@ -1,9 +1,27 @@
 from __future__ import annotations
 
-from quart import make_response, Blueprint
+import re
+import unicodedata
+
+from quart import make_response, request, g, Blueprint
 
 from shared.browser.app.authz import require_admin
 from shared.browser.app.utils.htmx import is_htmx_request
+from shared.services.registry import services
+from shared.sx.helpers import sx_response
+
+
+def _slugify(value: str, max_len: int = 255) -> str:
+    if value is None:
+        value = ""
+    value = unicodedata.normalize("NFKD", value)
+    value = value.encode("ascii", "ignore").decode("ascii")
+    value = value.lower()
+    value = value.replace("/", "-")
+    value = re.sub(r"[^a-z0-9]+", "-", value)
+    value = re.sub(r"-{2,}", "-", value)
+    value = value.strip("-")[:max_len].strip("-")
+    return value or "market"
 
 
 def register():
@@ -20,8 +38,51 @@ def register():
             html = await render_page_admin_page(tctx)
             return await make_response(html)
         else:
-            from shared.sx.helpers import sx_response
             sx_src = await render_page_admin_oob(tctx)
             return sx_response(sx_src)
 
+    @bp.post("/new/")
+    @require_admin
+    async def create_market(**kwargs):
+        form = await request.form
+        name = (form.get("name") or "").strip()
+
+        post_data = getattr(g, "post_data", None)
+        post_id = (post_data.get("post") or {}).get("id") if post_data else None
+
+        if not post_id:
+            return await make_response("No page context", 400)
+
+        slug = _slugify(name)
+
+        try:
+            await services.market.create_marketplace(g.s, "page", post_id, name, slug)
+        except Exception as e:
+            from shared.sx.jinja_bridge import render as render_comp
+            return await make_response(render_comp("error-inline", message=str(e)), 422)
+
+        from shared.sx.page import get_template_context
+        from sx.sx_components import render_markets_admin_list_panel
+        ctx = await get_template_context()
+        html = await render_markets_admin_list_panel(ctx)
+        return sx_response(html)
+
+    @bp.delete("/<market_slug>/")
+    @require_admin
+    async def delete_market(**kwargs):
+        market_slug = g.get("market_slug", "")
+        post_data = getattr(g, "post_data", None)
+        post_id = (post_data.get("post") or {}).get("id") if post_data else None
+
+        if not post_id:
+            return await make_response("No page context", 400)
+
+        await services.market.soft_delete_marketplace(g.s, "page", post_id, market_slug)
+
+        from shared.sx.page import get_template_context
+        from sx.sx_components import render_markets_admin_list_panel
+        ctx = await get_template_context()
+        html = await render_markets_admin_list_panel(ctx)
+        return sx_response(html)
+
     return bp