fix: implement express-ejs-layouts for proper template inheritance

ISSUE:
EJS v3+ removed ability to pass raw template strings to include()
Dashboard template used old pattern causing 'include is not a function' error

SOLUTION (per Gemini consultation):
1. Installed express-ejs-layouts package
2. Added expressLayouts middleware to index.js
3. Set default layout to 'layout'
4. layout.ejs already had <%- body %> injection point
5. Removed include() wrapper from dashboard.ejs (first/last lines)

FILES MODIFIED:
- services/arbiter-3.0/src/index.js (+4 lines - import and config)
- services/arbiter-3.0/src/views/admin/dashboard.ejs (-2 lines - wrapper removal)

TESTING:
Visit /admin after Discord OAuth - should render HTML dashboard

Credit: Gemini consultation - EJS v3+ layout pattern fix

Signed-off-by: Claude (Chronicler #57) <claude@firefrostgaming.com>

services/arbiter-3.0/src/index.js

@@ -1,5 +1,6 @@
 require('dotenv').config();
 const express = require('express');
+const expressLayouts = require('express-ejs-layouts');
 const session = require('express-session');
 const passport = require('passport');
 const DiscordStrategy = require('passport-discord').Strategy;
@@ -38,6 +39,10 @@ app.set('trust proxy', 1);
 app.set('view engine', 'ejs');
 app.set('views', __dirname + '/views');
 
+// Enable proper layout rendering with express-ejs-layouts
+app.use(expressLayouts);
+app.set('layout', 'layout'); // Default layout is views/layout.ejs
+
 // CRITICAL: Stripe webhook needs raw body BEFORE express.json() middleware
 // Mounted at /webhooks/stripe to avoid conflict with /stripe checkout mount
 app.use('/webhooks/stripe', stripeRoutes);

services/arbiter-3.0/src/views/admin/dashboard.ejs

@@ -1,4 +1,3 @@
-<%- include('../layout', { body: `
     <div class="grid grid-cols-1 md:grid-cols-4 gap-6 mb-6">
         <div class="bg-white dark:bg-darkcard rounded-lg shadow-sm border border-gray-200 dark:border-gray-700 p-6">
             <div class="text-sm text-gray-500 dark:text-gray-400">Active Subscribers</div>
@@ -27,4 +26,3 @@
             <strong>Fire + Frost + Foundation = Where Love Builds Legacy</strong>
         </p>
     </div>
-`}) %>