feat: Add SMTP settings and collapsible email configuration UI

- Add SMTP fields to TicketEmailSettings model (host, port, TLS/SSL, credentials, from email/name)
- Update serializers with SMTP fields and is_smtp_configured flag
- Add TicketEmailTestSmtpView for testing SMTP connections
- Update frontend API types and hooks for SMTP settings
- Add collapsible IMAP and SMTP configuration sections with "Configured" badges
- Fix TypeScript errors in mockData.ts (missing required fields, type mismatches)

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

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

smoothschedule/SCHEDULER_PLUGIN_SYSTEM.md

@@ -99,6 +99,80 @@ Global registry for managing plugins.
 - `list_all()` - List all plugins with metadata
 - `list_by_category()` - Group plugins by category
 
+#### Template Variables (`schedule/template_parser.py`)
+
+Template variables allow plugins to define configurable fields that users can fill in via the UI.
+
+**Variable Format:**
+```
+{{PROMPT:variable_name|description}}
+{{PROMPT:variable_name|description|default_value}}
+{{PROMPT:variable_name|description|default_value|type}}
+{{PROMPT:variable_name|description||type}}  (no default, explicit type)
+```
+
+**Supported Types:**
+
+| Type | Description | UI Component |
+|------|-------------|--------------|
+| `text` | Single-line text input | Text input |
+| `textarea` | Multi-line text input | Textarea |
+| `email` | Email address | Email input with validation |
+| `number` | Numeric value | Number input |
+| `url` | URL/webhook endpoint | URL input with validation |
+| `email_template` | Email template selector | Dropdown of email templates |
+
+**Type Inference:**
+If no explicit type is provided, the parser infers type from the variable name:
+- Names containing `email` → `email` type
+- Names containing `count`, `days`, `hours`, `amount` → `number` type
+- Names containing `url`, `webhook`, `endpoint` → `url` type
+- Names containing `message`, `body`, `content` → `textarea` type
+- Default → `text` type
+
+**Example - Email Template Variable:**
+```python
+# In your plugin script, reference an email template:
+template_id = {{PROMPT:confirmation_template|Email template for confirmations||email_template}}
+
+# The UI will show a dropdown of all available email templates
+# The user selects a template, and the template ID is stored in the config
+```
+
+**Using Email Templates in Plugins:**
+```python
+from schedule.models import EmailTemplate
+
+class MyNotificationPlugin(BasePlugin):
+    def execute(self, context):
+        template_id = self.config.get('confirmation_template')
+
+        if template_id:
+            template = EmailTemplate.objects.get(id=template_id)
+            subject, html, text = template.render({
+                'BUSINESS_NAME': context['business'].name,
+                'CUSTOMER_NAME': customer.name,
+                # ... other variables
+            })
+
+            # Send the email using the rendered template
+            send_email(recipient, subject, html, text)
+```
+
+**Insertion Codes (for use within templates):**
+
+These codes are replaced at runtime with actual values:
+- `{{BUSINESS_NAME}}` - Business name
+- `{{BUSINESS_EMAIL}}` - Business contact email
+- `{{BUSINESS_PHONE}}` - Business phone number
+- `{{CUSTOMER_NAME}}` - Customer's name
+- `{{CUSTOMER_EMAIL}}` - Customer's email
+- `{{APPOINTMENT_TIME}}` - Appointment date/time
+- `{{APPOINTMENT_DATE}}` - Appointment date only
+- `{{APPOINTMENT_SERVICE}}` - Service name
+- `{{TODAY}}` - Today's date
+- `{{NOW}}` - Current date and time
+
 ### 3. Celery Tasks (`schedule/tasks.py`)
 
 #### execute_scheduled_task(scheduled_task_id)
@@ -298,6 +372,11 @@ class MyCustomPlugin(BasePlugin):
             'default': 100,
             'description': 'Processing threshold',
         },
+        'notification_template': {
+            'type': 'email_template',
+            'required': False,
+            'description': 'Email template to use for notifications',
+        },
     }
 
     def execute(self, context):