fix: correct navigation links in shop error pages for multi-access routing

Fix broken links in shop error pages that were not respecting the base_url
for multi-access routing (domain, subdomain, and path-based vendor access).

Problem:
- Links used `{{ base_url or '/' }}` pattern which incorrectly fell back to '/'
- This broke navigation when accessing via path-based routing (e.g., /vendor/vendor1/)
- Links like "Continue Shopping" and "View All Products" went to wrong URLs

Solution:
- Remove `or '/'` fallback since base_url is always provided by error_renderer.py
- Add proper path prefixes (shop/, shop/products, shop/account/login, etc.)
- Ensure all links use `{{ base_url }}shop/...` pattern

Files Updated (10 templates):
- base.html: Fixed default action buttons and contact links
- 404.html: Fixed "Continue Shopping" and "View All Products" links
- 401.html: Fixed login and register links to use shop/account/* paths
- 403.html: Fixed login and home links
- 400.html: Fixed home and contact links
- 422.html: Fixed home and contact links
- 429.html: Fixed home and contact links
- 500.html: Fixed home and contact links
- 502.html: Fixed home and contact links
- generic.html: Fixed home and contact links

Example fix:
  Before: href="{{ base_url or '/' }}shop/products"
  After:  href="{{ base_url }}shop/products"

  Result for path-based access (/vendor/vendor1/):
  Before: /shop/products (wrong - ignores vendor context)
  After:  /vendor/vendor1/shop/products (correct)

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

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

app/templates/shop/errors/400.html

@@ -18,11 +18,11 @@
 
 <div class="action-buttons">
     <a href="javascript:history.back()" class="btn btn-primary">Go Back</a>
-    <a href="{{ base_url or '/' }}" class="btn btn-secondary">Go to Home</a>
+    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
 </div>
 
 <div class="support-link">
-    Need help? <a href="{{ base_url or '/' }}contact">Contact us</a>
+    Need help? <a href="{{ base_url }}shop/contact">Contact us</a>
 </div>
 
 {% if vendor %}

app/templates/shop/errors/401.html

@@ -17,12 +17,12 @@
 </div>
 
 <div class="action-buttons">
-    <a href="{{ base_url or '/' }}login" class="btn btn-primary">Log In</a>
-    <a href="{{ base_url or '/' }}register" class="btn btn-secondary">Create Account</a>
+    <a href="{{ base_url }}shop/account/login" class="btn btn-primary">Log In</a>
+    <a href="{{ base_url }}shop/account/register" class="btn btn-secondary">Create Account</a>
 </div>
 
 <div class="support-link">
-    Don't have an account? <a href="{{ base_url or '/' }}register">Sign up now</a>
+    Don't have an account? <a href="{{ base_url }}shop/account/register">Sign up now</a>
 </div>
 
 {% if vendor %}

app/templates/shop/errors/403.html

@@ -17,12 +17,12 @@
 </div>
 
 <div class="action-buttons">
-    <a href="{{ base_url or '/' }}login" class="btn btn-primary">Log In</a>
-    <a href="{{ base_url or '/' }}" class="btn btn-secondary">Go to Home</a>
+    <a href="{{ base_url }}shop/account/login" class="btn btn-primary">Log In</a>
+    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
 </div>
 
 <div class="support-link">
-    Need help accessing your account? <a href="{{ base_url or '/' }}contact">Contact support</a>
+    Need help accessing your account? <a href="{{ base_url }}shop/contact">Contact support</a>
 </div>
 
 {% if vendor %}

app/templates/shop/errors/404.html

@@ -17,12 +17,12 @@
 </div>
 
 <div class="action-buttons">
-    <a href="{{ base_url or '/' }}shop/" class="btn btn-primary">Continue Shopping</a>
-    <a href="{{ base_url or '/' }}shop/products" class="btn btn-secondary">View All Products</a>
+    <a href="{{ base_url }}shop/" class="btn btn-primary">Continue Shopping</a>
+    <a href="{{ base_url }}shop/products" class="btn btn-secondary">View All Products</a>
 </div>
 
 <div class="support-link">
-    Can't find what you're looking for? <a href="{{ base_url or '/' }}shop/contact">Contact us</a> and we'll help you find it.
+    Can't find what you're looking for? <a href="{{ base_url }}shop/contact">Contact us</a> and we'll help you find it.
 </div>
 
 {% if vendor %}

app/templates/shop/errors/422.html

@@ -31,11 +31,11 @@
 
 <div class="action-buttons">
     <a href="javascript:history.back()" class="btn btn-primary">Go Back and Fix</a>
-    <a href="{{ base_url or '/' }}" class="btn btn-secondary">Go to Home</a>
+    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
 </div>
 
 <div class="support-link">
-    Having trouble? <a href="{{ base_url or '/' }}contact">We're here to help</a>
+    Having trouble? <a href="{{ base_url }}shop/contact">We're here to help</a>
 </div>
 
 {% if vendor %}

app/templates/shop/errors/429.html

@@ -26,11 +26,11 @@
 
 <div class="action-buttons">
     <a href="javascript:location.reload()" class="btn btn-primary">Try Again</a>
-    <a href="{{ base_url or '/' }}" class="btn btn-secondary">Go to Home</a>
+    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
 </div>
 
 <div class="support-link">
-    Questions? <a href="{{ base_url or '/' }}contact">Contact us</a>
+    Questions? <a href="{{ base_url }}shop/contact">Contact us</a>
 </div>
 
 {% if vendor %}

app/templates/shop/errors/500.html

@@ -17,12 +17,12 @@
 </div>
 
 <div class="action-buttons">
-    <a href="{{ base_url or '/' }}" class="btn btn-primary">Go to Home</a>
+    <a href="{{ base_url }}shop/" class="btn btn-primary">Go to Home</a>
     <a href="javascript:location.reload()" class="btn btn-secondary">Try Again</a>
 </div>
 
 <div class="support-link">
-    Issue persisting? <a href="{{ base_url or '/' }}contact">Let us know</a> and we'll help you out.
+    Issue persisting? <a href="{{ base_url }}shop/contact">Let us know</a> and we'll help you out.
 </div>
 
 {% if vendor %}

app/templates/shop/errors/502.html

@@ -18,11 +18,11 @@
 
 <div class="action-buttons">
     <a href="javascript:location.reload()" class="btn btn-primary">Try Again</a>
-    <a href="{{ base_url or '/' }}" class="btn btn-secondary">Go to Home</a>
+    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
 </div>
 
 <div class="support-link">
-    If this continues, <a href="{{ base_url or '/' }}contact">let us know</a>
+    If this continues, <a href="{{ base_url }}shop/contact">let us know</a>
 </div>
 
 {% if vendor %}

app/templates/shop/errors/base.html

@@ -171,8 +171,8 @@
 
         <div class="action-buttons">
             {% block action_buttons %}
-            <a href="{{ base_url or '/' }}" class="btn btn-primary">Continue Shopping</a>
-            <a href="{{ base_url or '/' }}contact" class="btn btn-secondary">Contact Us</a>
+            <a href="{{ base_url }}shop/" class="btn btn-primary">Continue Shopping</a>
+            <a href="{{ base_url }}shop/contact" class="btn btn-secondary">Contact Us</a>
             {% endblock %}
         </div>
 
@@ -180,7 +180,7 @@
 
         <div class="support-link">
             {% block support_link %}
-            Need help? <a href="{{ base_url or '/' }}contact">Contact our support team</a>
+            Need help? <a href="{{ base_url }}shop/contact">Contact our support team</a>
             {% endblock %}
         </div>
 

app/templates/shop/errors/generic.html

@@ -15,12 +15,12 @@
 <div class="error-message">{{ message }}</div>
 
 <div class="action-buttons">
-    <a href="{{ base_url or '/' }}" class="btn btn-primary">Continue Shopping</a>
+    <a href="{{ base_url }}shop/" class="btn btn-primary">Continue Shopping</a>
     <a href="javascript:history.back()" class="btn btn-secondary">Go Back</a>
 </div>
 
 <div class="support-link">
-    Need assistance? <a href="{{ base_url or '/' }}contact">Contact us</a>
+    Need assistance? <a href="{{ base_url }}shop/contact">Contact us</a>
 </div>
 
 {% if vendor %}