feat: Add comprehensive ANTLR build integration and watch capabilities

�� Major ANTLR System Enhancements:

## New Features:
- ✅ Generic ANTLR generation system (scripts/antlr-generate.mts)
- ✅ Dedicated watch command for grammar development (scripts/antlr-watch.mts)
- ✅ Build pipeline integration with postinstall hooks
- ✅ Development server watch integration for .g4 files
- ✅ Sequence diagram ANTLR parser implementation

## Build Integration:
- 🏗️ Added ANTLR generation to build process (.esbuild/build.ts)
- 📦 Added postinstall hooks to package.json files
- 🔄 Integrated ANTLR generation with dev server (.esbuild/server-antlr.ts)
- 🎯 Smart path detection for root vs package directory execution

## New Commands:
- `pnpm antlr:generate` - Generic generation for all diagrams
- `pnpm antlr:watch` - Grammar development with file watching
- Auto-generation during `pnpm install` and `pnpm build`

## Documentation:
- 📖 Consolidated all ANTLR docs into ANTLR_SETUP.md
- 🗑️ Removed duplicate ANTLR_GENERATION.md
- 📋 Added comprehensive troubleshooting and usage guides
- 🎯 Updated with build integration and watch functionality

## Parser Implementations:
- 🔄 Enhanced sequence diagram ANTLR parser with dual-pattern support
- 🛠️ Added SequenceListener, SequenceVisitor, SequenceParserCore
- ⚡ Improved flowchart parser integration and error handling

## Benefits:
- 🔄 Zero manual steps - ANTLR files always generated automatically
- ⚡ Fast grammar development with watch mode
- 🎯 Unified workflow for all diagram types
- 🛡️ CI/CD ready with build integration
- 📊 Clear feedback and comprehensive logging

This establishes a complete, production-ready ANTLR development workflow!

scripts/antlr-watch.mts

@@ -0,0 +1,122 @@
+#!/usr/bin/env tsx
+/* eslint-disable no-console */
+
+import chokidar from 'chokidar';
+import { execSync } from 'child_process';
+
+/**
+ * ANTLR Watch Script
+ *
+ * This script generates ANTLR files and then watches for changes to .g4 grammar files,
+ * automatically regenerating the corresponding parsers when changes are detected.
+ *
+ * Features:
+ * - Initial generation of all ANTLR files
+ * - Watch .g4 files for changes
+ * - Debounced regeneration to avoid multiple builds
+ * - Clear logging and progress reporting
+ * - Graceful shutdown handling
+ */
+
+let isGenerating = false;
+let timeoutID: NodeJS.Timeout | undefined = undefined;
+
+/**
+ * Generate ANTLR parser files from grammar files
+ */
+function generateAntlr(): void {
+  if (isGenerating) {
+    console.log('⏳ ANTLR generation already in progress, skipping...');
+    return;
+  }
+
+  try {
+    isGenerating = true;
+    console.log('🎯 ANTLR: Generating parser files...');
+    execSync('tsx scripts/antlr-generate.mts', { stdio: 'inherit' });
+    console.log('✅ ANTLR: Parser files generated successfully\n');
+  } catch (error) {
+    console.error('❌ ANTLR: Failed to generate parser files:', error);
+  } finally {
+    isGenerating = false;
+  }
+}
+
+/**
+ * Handle file change events with debouncing
+ */
+function handleFileChange(path: string): void {
+  if (timeoutID !== undefined) {
+    clearTimeout(timeoutID);
+  }
+
+  console.log(`🎯 Grammar file changed: ${path}`);
+
+  // Debounce file changes to avoid multiple regenerations
+  timeoutID = setTimeout(() => {
+    console.log('🔄 Regenerating ANTLR files...\n');
+    generateAntlr();
+    timeoutID = undefined;
+  }, 500); // 500ms debounce
+}
+
+/**
+ * Setup graceful shutdown
+ */
+function setupGracefulShutdown(): void {
+  const shutdown = () => {
+    console.log('\n🛑 Shutting down ANTLR watch...');
+    if (timeoutID) {
+      clearTimeout(timeoutID);
+    }
+    process.exit(0);
+  };
+
+  process.on('SIGINT', shutdown);
+  process.on('SIGTERM', shutdown);
+}
+
+/**
+ * Main function
+ */
+function main(): void {
+  console.log('🚀 ANTLR Watch - Generate and watch grammar files for changes\n');
+
+  // Setup graceful shutdown
+  setupGracefulShutdown();
+
+  // Initial generation
+  generateAntlr();
+
+  // Setup file watcher
+  console.log('👀 Watching for .g4 file changes...');
+  console.log('📁 Pattern: **/src/**/parser/antlr/*.g4');
+  console.log('🛑 Press Ctrl+C to stop watching\n');
+
+  const watcher = chokidar.watch('**/src/**/parser/antlr/*.g4', {
+    ignoreInitial: true,
+    ignored: [/node_modules/, /dist/, /docs/, /coverage/],
+    persistent: true,
+  });
+
+  watcher
+    .on('change', handleFileChange)
+    .on('add', handleFileChange)
+    .on('error', (error) => {
+      console.error('❌ Watcher error:', error);
+    })
+    .on('ready', () => {
+      console.log('✅ Watcher ready - monitoring grammar files for changes...\n');
+    });
+
+  // Keep the process alive
+  process.stdin.resume();
+}
+
+// Run the script
+if (import.meta.url === `file://${process.argv[1]}`) {
+  main().catch((error) => {
+    console.error('❌ Fatal error:', error);
+    process.exit(1);
+  });
+}