refactor: migrate to modular tool-based architecture

- Implement tool registry system with individual tool modules
- Reorganize transformers into categorized source modules
- Remove emojiLibrary.js, consolidate into EmojiUtils and emojiData
- Fix mobile close button and tooltip functionality
- Add build system for transforms and emoji data
- Migrate from Python backend to pure JavaScript
- Add comprehensive documentation and testing
- Improve code organization and maintainability
- Ignore generated files (transforms-bundle.js, emojiData.js)

build/inject-tool-scripts.js

@@ -0,0 +1,92 @@
+#!/usr/bin/env node
+/**
+ * Auto-discover and inject tool script tags into index.template.html
+ * Also generates auto-registration code for toolRegistry.js
+ */
+
+const fs = require('fs');
+const path = require('path');
+
+console.log('🔧 Auto-discovering tools and generating script tags...\n');
+
+const toolsDir = path.join(__dirname, '../js/tools');
+const templatePath = path.join(__dirname, '../index.template.html');
+const registryPath = path.join(__dirname, '../js/core/toolRegistry.js');
+
+// Discover all tool files (excluding Tool.js base class)
+const toolFiles = fs.readdirSync(toolsDir)
+    .filter(file => file.endsWith('Tool.js') && file !== 'Tool.js')
+    .sort(); // Sort for consistent ordering
+
+console.log(`📦 Found ${toolFiles.length} tools:`);
+toolFiles.forEach(file => console.log(`   - ${file}`));
+
+// Generate script tags
+const scriptTags = toolFiles.map(file => 
+    `    <script src="js/tools/${file}"></script>`
+).join('\n');
+
+// Read index.template.html
+let templateContent = fs.readFileSync(templatePath, 'utf8');
+
+// Find the tool scripts section (between Tool.js and toolRegistry.js)
+const toolJsMarker = '<script src="js/tools/Tool.js"></script>';
+const registryMarker = '<script src="js/core/toolRegistry.js"></script>';
+
+const toolJsIndex = templateContent.indexOf(toolJsMarker);
+const registryIndex = templateContent.indexOf(registryMarker);
+
+if (toolJsIndex === -1 || registryIndex === -1) {
+    console.error('\n❌ Could not find tool script markers in index.template.html');
+    process.exit(1);
+}
+
+// Extract the section between Tool.js and toolRegistry.js
+const before = templateContent.substring(0, toolJsIndex + toolJsMarker.length);
+const after = templateContent.substring(registryIndex);
+
+// Replace with dynamic script tags
+const newTemplateContent = before + '\n' + scriptTags + '\n' + after;
+
+// Write updated template
+fs.writeFileSync(templatePath, newTemplateContent, 'utf8');
+console.log('\n✅ Updated index.template.html with dynamic tool script tags');
+
+// Generate auto-registration code
+const registrationCode = toolFiles.map(file => {
+    // Extract class name from filename (e.g., "TransformTool.js" -> "TransformTool")
+    const className = file.replace('.js', '');
+    return `if (typeof ${className} !== 'undefined') {
+    window.toolRegistry.register(new ${className}());
+}`;
+}).join('\n');
+
+// Read toolRegistry.js
+let registryContent = fs.readFileSync(registryPath, 'utf8');
+
+// Find and replace the manual registration section
+const autoRegisterStart = '// Auto-register tools if they\'re available';
+const autoRegisterEnd = '// Export for module systems';
+
+const startIndex = registryContent.indexOf(autoRegisterStart);
+const endIndex = registryContent.indexOf(autoRegisterEnd);
+
+if (startIndex === -1 || endIndex === -1) {
+    console.error('\n❌ Could not find auto-registration section in toolRegistry.js');
+    process.exit(1);
+}
+
+// Replace with dynamic registration
+const beforeRegistry = registryContent.substring(0, startIndex);
+const afterRegistry = registryContent.substring(endIndex);
+
+const newRegistryContent = beforeRegistry + 
+    autoRegisterStart + '\n' + 
+    registrationCode + '\n\n' + 
+    afterRegistry;
+
+// Write updated registry
+fs.writeFileSync(registryPath, newRegistryContent, 'utf8');
+console.log('✅ Updated toolRegistry.js with dynamic tool registration');
+console.log(`\n✨ ${toolFiles.length} tools auto-discovered and registered!\n`);
+