Add global + page-scoped market listings with infinite scroll

- New all_markets blueprint at / with paginated grid and HTMX infinite scroll
- New page_markets blueprint at /<slug>/ for page-scoped market listing
- list_marketplaces service method (via shared submodule update)
- Updated slug preprocessor to handle both /<slug>/ and /<page_slug>/<market_slug>/
- Removed inline markets_listing() route (replaced by all_markets blueprint)

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

templates/_types/all_markets/_card.html

@@ -0,0 +1,33 @@
+{# Card for a single market in the global listing #}
+{% set pi = page_info.get(market.container_id, {}) %}
+{% set page_slug = pi.get('slug', '') %}
+{% set page_title = pi.get('title') %}
+{% if page_slug %}
+  {% set market_href = market_url('/' ~ page_slug ~ '/' ~ market.slug ~ '/') %}
+{% else %}
+  {% set market_href = '' %}
+{% endif %}
+<article class="rounded-xl bg-white shadow-sm border border-stone-200 p-5 flex flex-col justify-between hover:border-stone-400 transition-colors">
+  <div>
+    {% if market_href %}
+      <a href="{{ market_href }}" class="hover:text-emerald-700">
+        <h2 class="text-lg font-semibold text-stone-900">{{ market.name }}</h2>
+      </a>
+    {% else %}
+      <h2 class="text-lg font-semibold text-stone-900">{{ market.name }}</h2>
+    {% endif %}
+
+    {% if market.description %}
+      <p class="text-sm text-stone-600 mt-1 line-clamp-2">{{ market.description }}</p>
+    {% endif %}
+  </div>
+
+  <div class="flex flex-wrap items-center gap-1.5 mt-3">
+    {% if page_title %}
+      <a href="{{ market_url('/' ~ page_slug ~ '/') }}"
+         class="inline-block px-2 py-0.5 rounded-full text-xs font-medium bg-amber-100 text-amber-800 hover:bg-amber-200">
+        {{ page_title }}
+      </a>
+    {% endif %}
+  </div>
+</article>

templates/_types/all_markets/_cards.html

@@ -0,0 +1,18 @@
+{% for market in markets %}
+  {% include "_types/all_markets/_card.html" %}
+{% endfor %}
+{% if has_more %}
+  {# Infinite scroll sentinel #}
+  {% set next_url = url_for('all_markets.markets_fragment', page=page + 1)|host %}
+  <div
+    id="sentinel-{{ page }}"
+    class="h-4 opacity-0 pointer-events-none"
+    hx-get="{{ next_url }}"
+    hx-trigger="intersect once delay:250ms"
+    hx-swap="outerHTML"
+    role="status"
+    aria-hidden="true"
+  >
+    <div class="text-center text-xs text-stone-400">loading...</div>
+  </div>
+{% endif %}

templates/_types/all_markets/_main_panel.html

@@ -0,0 +1,12 @@
+{# Markets grid #}
+{% if markets %}
+  <div class="max-w-full px-3 py-3 grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 gap-4">
+    {% include "_types/all_markets/_cards.html" %}
+  </div>
+{% else %}
+  <div class="px-3 py-12 text-center text-stone-400">
+    <i class="fa fa-store text-4xl mb-3" aria-hidden="true"></i>
+    <p class="text-lg">No markets available</p>
+  </div>
+{% endif %}
+<div class="pb-8"></div>

templates/_types/all_markets/index.html

@@ -0,0 +1,7 @@
+{% extends '_types/root/_index.html' %}
+
+{% block meta %}{% endblock %}
+
+{% block content %}
+  {% include '_types/all_markets/_main_panel.html' %}
+{% endblock %}

templates/_types/page_markets/_card.html

@@ -0,0 +1,13 @@
+{# Card for a single market in a page-scoped listing #}
+{% set market_href = market_url('/' ~ post.slug ~ '/' ~ market.slug ~ '/') %}
+<article class="rounded-xl bg-white shadow-sm border border-stone-200 p-5 flex flex-col justify-between hover:border-stone-400 transition-colors">
+  <div>
+    <a href="{{ market_href }}" class="hover:text-emerald-700">
+      <h2 class="text-lg font-semibold text-stone-900">{{ market.name }}</h2>
+    </a>
+
+    {% if market.description %}
+      <p class="text-sm text-stone-600 mt-1 line-clamp-2">{{ market.description }}</p>
+    {% endif %}
+  </div>
+</article>

templates/_types/page_markets/_cards.html

@@ -0,0 +1,18 @@
+{% for market in markets %}
+  {% include "_types/page_markets/_card.html" %}
+{% endfor %}
+{% if has_more %}
+  {# Infinite scroll sentinel #}
+  {% set next_url = url_for('page_markets.markets_fragment', page=page + 1)|host %}
+  <div
+    id="sentinel-{{ page }}"
+    class="h-4 opacity-0 pointer-events-none"
+    hx-get="{{ next_url }}"
+    hx-trigger="intersect once delay:250ms"
+    hx-swap="outerHTML"
+    role="status"
+    aria-hidden="true"
+  >
+    <div class="text-center text-xs text-stone-400">loading...</div>
+  </div>
+{% endif %}

templates/_types/page_markets/_main_panel.html

@@ -0,0 +1,12 @@
+{# Markets grid for a single page #}
+{% if markets %}
+  <div class="max-w-full px-3 py-3 grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 gap-4">
+    {% include "_types/page_markets/_cards.html" %}
+  </div>
+{% else %}
+  <div class="px-3 py-12 text-center text-stone-400">
+    <i class="fa fa-store text-4xl mb-3" aria-hidden="true"></i>
+    <p class="text-lg">No markets for this page</p>
+  </div>
+{% endif %}
+<div class="pb-8"></div>

templates/_types/page_markets/index.html

@@ -0,0 +1,15 @@
+{% extends '_types/root/_index.html' %}
+
+{% block meta %}{% endblock %}
+
+{% block root_header_child %}
+  {% from '_types/root/_n/macros.html' import index_row with context %}
+  {% call index_row('post-header-child', '_types/post/header/_header.html') %}
+    {% block post_header_child %}
+    {% endblock %}
+  {% endcall %}
+{% endblock %}
+
+{% block content %}
+  {% include '_types/page_markets/_main_panel.html' %}
+{% endblock %}