feat: Complete Mail Composer with EmailJS integration

- Rich email composer with formatting tools (bold, italic, underline, links)
- Multi-recipient support (To, CC, BCC fields)
- File attachments with drag & drop support
- Priority levels and email validation
- Draft management with auto-save and cloud sync
- Real email sending via EmailJS integration
- Responsive design for mobile and desktop
- Comprehensive error handling and fallback modes
- Complete documentation and setup guides
- Firebase integration ready for advanced features

Features:
✅ Real email sending (EmailJS)
✅ Rich text editor
✅ File attachments
✅ Draft management
✅ Form validation
✅ Responsive UI
✅ Error handling
✅ Documentation

firebase.json

@@ -0,0 +1,37 @@
+{
+  "projects": {
+    "default": "your-project-id"
+  },
+  "targets": {},
+  "etags": {},
+  "hosting": {
+    "public": "dist",
+    "ignore": [
+      "firebase.json",
+      "**/.*",
+      "**/node_modules/**"
+    ],
+    "rewrites": [
+      {
+        "source": "**",
+        "destination": "/index.html"
+      }
+    ]
+  },
+  "functions": [
+    {
+      "source": "functions",
+      "codebase": "default",
+      "ignore": [
+        "node_modules",
+        ".git",
+        "firebase-debug.log",
+        "firebase-debug.*.log"
+      ]
+    }
+  ],
+  "firestore": {
+    "rules": "firestore.rules",
+    "indexes": "firestore.indexes.json"
+  }
+}