feat: Add plugin configuration editing with template variable parsing

## Backend Changes:
- Enhanced PluginTemplate.save() to auto-parse template variables from plugin code
- Updated PluginInstallationSerializer to expose template metadata (description, category, version, author, logo, template_variables)
- Fixed template variable parser to handle nested {{ }} braces in default values
- Added brace-counting algorithm to properly extract variables with insertion codes
- Fixed explicit type parameter detection (textarea, text, email, etc.)
- Made scheduled_task optional on PluginInstallation model
- Added EventPlugin through model for event-plugin relationships
- Added Event.execute_plugins() method for plugin automation

## Frontend Changes:
- Created Tasks.tsx page for managing scheduled tasks
- Enhanced MyPlugins page with clickable plugin cards
- Added edit configuration modal with dynamic form generation
- Implemented escape sequence handling (convert \n, \', etc. for display)
- Added plugin logos to My Plugins page
- Updated type definitions for PluginInstallation interface
- Added insertion code documentation to Plugin Docs

## Plugin System:
- All platform plugins now have editable email templates with textarea support
- Template variables properly parsed with full default values
- Insertion codes ({{CUSTOMER_NAME}}, {{BUSINESS_NAME}}, etc.) documented
- Plugin logos displayed in marketplace and My Plugins

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

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

frontend/public/plugin-logos/generate_with_imagen.py

@@ -0,0 +1,146 @@
+#!/usr/bin/env python3
+import os
+import sys
+import requests
+import base64
+import time
+from pathlib import Path
+
+# Imagen API configuration
+API_KEY = "AIzaSyB-nR0nkeftKrd42NrNIDcFCj3yFP8JLtw"
+MODEL = "imagen-4.0-generate-preview-06-06"
+API_URL = f"https://generativelanguage.googleapis.com/v1beta/models/{MODEL}:predict"
+
+OUTPUT_DIR = "/home/poduck/Desktop/smoothschedule2/frontend/public/plugin-logos"
+
+# Plugin configurations
+plugins = [
+    {
+        'filename': 'daily-appointment-summary.png',
+        'prompt': '''A modern, minimalist app icon for "Daily Appointment Summary Email" plugin.
+Square format with rounded corners. Indigo blue gradient background (#4f46e5).
+White icon showing a combination of an envelope and a calendar.
+Flat design, clean lines, professional SaaS application style.
+The icon should be simple and recognizable at small sizes.'''
+    },
+    {
+        'filename': 'no-show-tracker.png',
+        'prompt': '''A modern, minimalist app icon for "No-Show Customer Tracker" plugin.
+Square format with rounded corners. Red gradient background (#dc2626).
+White icon showing a person silhouette with an X or cancel symbol overlay.
+Flat design, clean lines, professional SaaS application style.
+The icon should convey missed appointments clearly at small sizes.'''
+    },
+    {
+        'filename': 'birthday-greetings.png',
+        'prompt': '''A modern, minimalist app icon for "Birthday Greeting Campaign" plugin.
+Square format with rounded corners. Pink gradient background (#ec4899).
+White icon showing a birthday cake or gift box with a bow.
+Flat design, clean lines, cheerful yet professional style.
+The icon should be celebratory and friendly at small sizes.'''
+    },
+    {
+        'filename': 'monthly-revenue-report.png',
+        'prompt': '''A modern, minimalist app icon for "Monthly Revenue Report" plugin.
+Square format with rounded corners. Green gradient background (#10b981).
+White icon showing an upward trending chart or bar graph.
+Flat design, clean lines, professional business analytics style.
+The icon should convey growth and success at small sizes.'''
+    },
+    {
+        'filename': 'appointment-reminder-24hr.png',
+        'prompt': '''A modern, minimalist app icon for "Appointment Reminder" plugin.
+Square format with rounded corners. Amber/orange gradient background (#f59e0b).
+White icon showing a notification bell with a small red badge or alert dot.
+Flat design, clean lines, attention-grabbing yet professional style.
+The icon should convey alerts and reminders clearly at small sizes.'''
+    },
+    {
+        'filename': 'inactive-customer-reengagement.png',
+        'prompt': '''A modern, minimalist app icon for "Inactive Customer Re-engagement" plugin.
+Square format with rounded corners. Purple gradient background (#8b5cf6).
+White icon showing a heart with a circular refresh arrow around it.
+Flat design, clean lines, warm and welcoming professional style.
+The icon should convey customer care and return at small sizes.'''
+    }
+]
+
+def generate_image(prompt, filename):
+    """Generate an image using Imagen API"""
+    print(f"\nGenerating {filename}...")
+
+    headers = {
+        "Content-Type": "application/json"
+    }
+
+    payload = {
+        "instances": [{
+            "prompt": prompt
+        }],
+        "parameters": {
+            "sampleCount": 1
+        }
+    }
+
+    try:
+        response = requests.post(
+            f"{API_URL}?key={API_KEY}",
+            headers=headers,
+            json=payload,
+            timeout=120
+        )
+
+        if response.status_code == 200:
+            result = response.json()
+
+            # Check if there's an image in the predictions
+            if 'predictions' in result and len(result['predictions']) > 0:
+                prediction = result['predictions'][0]
+                if 'bytesBase64Encoded' in prediction:
+                    # Extract and save the image
+                    image_data = base64.b64decode(prediction['bytesBase64Encoded'])
+                    output_path = os.path.join(OUTPUT_DIR, filename)
+                    with open(output_path, 'wb') as f:
+                        f.write(image_data)
+                    print(f"✓ Saved: {output_path} ({len(image_data)} bytes)")
+                    return True
+                elif 'image' in prediction and 'bytesBase64Encoded' in prediction['image']:
+                    image_data = base64.b64decode(prediction['image']['bytesBase64Encoded'])
+                    output_path = os.path.join(OUTPUT_DIR, filename)
+                    with open(output_path, 'wb') as f:
+                        f.write(image_data)
+                    print(f"✓ Saved: {output_path} ({len(image_data)} bytes)")
+                    return True
+
+            print(f"✗ No image generated. Response: {str(result)[:300]}...")
+            return False
+        else:
+            print(f"✗ API Error ({response.status_code}): {response.text[:500]}")
+            return False
+
+    except Exception as e:
+        print(f"✗ Error: {str(e)}")
+        return False
+
+def main():
+    # Create output directory
+    os.makedirs(OUTPUT_DIR, exist_ok=True)
+
+    print("Starting logo generation with Imagen 4.0 API...")
+    print("=" * 60)
+
+    success_count = 0
+    for i, plugin in enumerate(plugins):
+        if i > 0:
+            # Add delay between requests to avoid rate limiting
+            print("Waiting 2 seconds before next request...")
+            time.sleep(2)
+
+        if generate_image(plugin['prompt'], plugin['filename']):
+            success_count += 1
+
+    print("\n" + "=" * 60)
+    print(f"Generation complete: {success_count}/{len(plugins)} successful")
+
+if __name__ == "__main__":
+    main()