Inline ticket +/- updates without full page refresh

Extract shared _ticket_widget.html with stable #page-ticket-{id} target.
Adjust route returns re-rendered widget + OOB cart-mini swap, same
pattern as the entry detail page's ticket adjust.

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

bp/page/routes.py

@@ -9,7 +9,7 @@ Routes:
 """
 from __future__ import annotations
 
-from quart import Blueprint, g, request, render_template, make_response
+from quart import Blueprint, g, request, render_template, render_template_string, make_response
 
 from shared.browser.app.utils.htmx import is_htmx_request
 from shared.infrastructure.cart_identity import current_cart_identity
@@ -81,7 +81,7 @@ def register() -> Blueprint:
 
     @bp.post("/tickets/adjust")
     async def adjust_ticket():
-        """Adjust ticket quantity and refresh the page."""
+        """Adjust ticket quantity, return updated widget + OOB cart-mini."""
         ident = current_cart_identity()
         form = await request.form
         entry_id = int(form.get("entry_id", 0))
@@ -96,8 +96,33 @@ def register() -> Blueprint:
             ticket_type_id=ticket_type_id,
         )
 
-        resp = await make_response("", 200)
-        resp.headers["HX-Refresh"] = "true"
-        return resp
+        # Get updated ticket count for this entry
+        tickets = await services.calendar.pending_tickets(
+            g.s, user_id=ident["user_id"], session_id=ident["session_id"],
+        )
+        qty = sum(1 for t in tickets if t.entry_id == entry_id)
+
+        # Load entry DTO for the widget template
+        entry = await services.calendar.entry_by_id(g.s, entry_id)
+
+        # Updated cart count for OOB mini-cart
+        summary = await services.cart.cart_summary(
+            g.s, user_id=ident["user_id"], session_id=ident["session_id"],
+        )
+        cart_count = summary.count + summary.calendar_count + summary.ticket_count
+
+        # Render widget + OOB cart-mini
+        widget_html = await render_template(
+            "_types/page_summary/_ticket_widget.html",
+            entry=entry,
+            qty=qty,
+            ticket_url=f"/{g.post_slug}/tickets/adjust",
+        )
+        mini_html = await render_template_string(
+            '{% from "_types/cart/_mini.html" import mini with context %}'
+            '{{ mini(oob="true") }}',
+            cart_count=cart_count,
+        )
+        return await make_response(widget_html + mini_html, 200)
 
     return bp