feat: Add presence heartbeat for Matrix online status

- matrix-gateway: POST /internal/matrix/presence/online endpoint
- usePresenceHeartbeat hook with activity tracking
- Auto away after 5 min inactivity
- Offline on page close/visibility change
- Integrated in MatrixChatRoom component

node-network-app/node_modules/function-bind/test/.eslintrc

@@ -0,0 +1,9 @@
+{
+	"rules": {
+		"array-bracket-newline": 0,
+		"array-element-newline": 0,
+		"max-statements-per-line": [2, { "max": 2 }],
+		"no-invalid-this": 0,
+		"no-magic-numbers": 0,
+	}
+}