Fix host welcome email using dark text on dark background; v2.0.13

Body text was #2c2417 (near-black) rendered inside the dark branded
email wrapper (#0f0f0c). Updated to light colors matching the template:
#c8c0ac for body, #f0ead8 for emphasis, #1a1a15/#2a2518 for table cells.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "2.0.12",
+  "version": "2.0.13",
   "type": "module",
   "scripts": {
     "dev": "vite",