Refactor: Use @simpleworkjs/conf for configuration

- Replace ENV vars with proper config system
- Add conf/ directory with base, development, production, secrets
- Add secrets.example.js template
- Update .gitignore for secrets.js
- Show environment in startup banner

conf/production.js

@@ -0,0 +1,22 @@
+/**
+ * Production environment configuration
+ */
+
+module.exports = {
+  server: {
+    // Use PORT env var if set, otherwise default
+    port: parseInt(process.env.PORT) || 3000
+  },
+  
+  session: {
+    // Should be set via secrets.js in production
+    secret: process.env.SESSION_SECRET || 'CHANGE-ME-NOW'
+  },
+  
+  auth: {
+    disabled: false,
+    ldap: {
+      enabled: process.env.LDAP_ENABLED === 'true'
+    }
+  }
+};