feat(source2): push all latest files - device labeling, help system, proxy docs, database isolation fix

- Added DOKUMENTASI-FILTER-PER-SITE.md (site isolation docs)
- Fixed start-with-env.js to force-load .env.production
- Fixed MONGODB_URI hostname from mongodb-netify to mongodb.prod.proit.id
- Updated .gitignore to exclude sensitive scripts and credential files
- Minor UI and labeling improvements

backend/models/Session.js

@@ -0,0 +1,22 @@
+// backend/models/Session.js
+// ─────────────────────────────────────────────────────────────────────────────
+// MongoDB User Session Schema for remote revocation capability
+// ─────────────────────────────────────────────────────────────────────────────
+
+const mongoose = require('mongoose');
+
+const SessionSchema = new mongoose.Schema({
+  user_id: { type: mongoose.Schema.Types.ObjectId, ref: 'User', required: true, index: true },
+  ip_address: { type: String, default: 'Unknown' },
+  user_agent: { type: String, default: 'Unknown' },
+  session_token: { type: String, required: true, unique: true }, // JWT JTI or unique token hash
+  last_active: { type: Date, default: Date.now },
+  expires_at: { type: Date, required: true }, // MongoDB TTL Index specified below via SessionSchema.index
+}, {
+  timestamps: { createdAt: 'created_at', updatedAt: 'updated_at' }
+});
+
+// TTL index to automatically remove expired sessions from MongoDB
+SessionSchema.index({ expires_at: 1 }, { expireAfterSeconds: 0 });
+
+module.exports = mongoose.model('Session', SessionSchema);