fix: use table_header_custom for custom headers in subscription pages

The table_header() macro doesn't support caller() - it takes a columns list.
Using {% call table_header() %} caused a Jinja2 error:
  "macro 'table_header' was invoked with two values for the special caller argument"

Changes:
- Add table_header_custom() macro that supports caller() for custom headers
- Update subscriptions.html, subscription-tiers.html, billing-history.html
- Add TPL-008 architecture rule to detect this pattern
- Renumber TPL-009 (block names) and TPL-010 (Alpine vars)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/templates/admin/billing-history.html

@@ -2,7 +2,7 @@
 {% extends "admin/base.html" %}
 {% from 'shared/macros/alerts.html' import alert_dynamic, error_state %}
 {% from 'shared/macros/headers.html' import page_header_refresh %}
-{% from 'shared/macros/tables.html' import table_wrapper, table_header, th_sortable %}
+{% from 'shared/macros/tables.html' import table_wrapper, table_header_custom, th_sortable %}
 {% from 'shared/macros/pagination.html' import pagination_full %}
 
 {% block title %}Billing History{% endblock %}
@@ -107,7 +107,7 @@
 <!-- Invoices Table -->
 {% call table_wrapper() %}
     <table class="w-full whitespace-nowrap">
-        {% call table_header() %}
+        {% call table_header_custom() %}
             {{ th_sortable('invoice_date', 'Date', 'sortBy', 'sortOrder') }}
             <th class="px-4 py-3">Invoice #</th>
             {{ th_sortable('vendor_name', 'Vendor', 'sortBy', 'sortOrder') }}

app/templates/admin/subscription-tiers.html

@@ -3,7 +3,7 @@
 {% extends "admin/base.html" %}
 {% from 'shared/macros/alerts.html' import alert_dynamic, error_state %}
 {% from 'shared/macros/headers.html' import page_header_refresh %}
-{% from 'shared/macros/tables.html' import table_wrapper, table_header, th_sortable, empty_state %}
+{% from 'shared/macros/tables.html' import table_wrapper, table_header_custom, th_sortable, empty_state %}
 {% from 'shared/macros/modals.html' import modal_confirm %}
 
 {% block title %}Subscription Tiers{% endblock %}
@@ -85,7 +85,7 @@
 <!-- Tiers Table -->
 {% call table_wrapper() %}
     <table class="w-full whitespace-nowrap">
-        {% call table_header() %}
+        {% call table_header_custom() %}
             <th class="px-4 py-3">#</th>
             {{ th_sortable('code', 'Code', 'sortBy', 'sortOrder') }}
             {{ th_sortable('name', 'Name', 'sortBy', 'sortOrder') }}

app/templates/admin/subscriptions.html

@@ -2,7 +2,7 @@
 {% extends "admin/base.html" %}
 {% from 'shared/macros/alerts.html' import alert_dynamic, error_state %}
 {% from 'shared/macros/headers.html' import page_header_refresh %}
-{% from 'shared/macros/tables.html' import table_wrapper, table_header, th_sortable %}
+{% from 'shared/macros/tables.html' import table_wrapper, table_header_custom, th_sortable %}
 {% from 'shared/macros/pagination.html' import pagination_full %}
 
 {% block title %}Vendor Subscriptions{% endblock %}
@@ -139,7 +139,7 @@
 <!-- Subscriptions Table -->
 {% call table_wrapper() %}
     <table class="w-full whitespace-nowrap">
-        {% call table_header() %}
+        {% call table_header_custom() %}
             {{ th_sortable('vendor_name', 'Vendor', 'sortBy', 'sortOrder') }}
             {{ th_sortable('tier', 'Tier', 'sortBy', 'sortOrder') }}
             {{ th_sortable('status', 'Status', 'sortBy', 'sortOrder') }}

app/templates/shared/macros/tables.html

@@ -48,6 +48,27 @@
 {% endmacro %}
 
 
+{#
+  Custom Table Header
+  ===================
+  Renders a table header with custom content via caller().
+  Use this when you need th_sortable or custom th elements.
+
+  Usage:
+    {% call table_header_custom() %}
+        {{ th_sortable('name', 'Name', 'sortBy', 'sortOrder') }}
+        <th class="px-4 py-3">Actions</th>
+    {% endcall %}
+#}
+{% macro table_header_custom() %}
+<thead>
+    <tr class="text-xs font-semibold tracking-wide text-left text-gray-500 uppercase border-b dark:border-gray-700 bg-gray-50 dark:text-gray-400 dark:bg-gray-800">
+        {{ caller() }}
+    </tr>
+</thead>
+{% endmacro %}
+
+
 {#
   Sortable Table Header
   =====================