feat: essential configuration options for deployers

This commit makes everything a ton easier for deployers, adding
configuration options to allow nip.io domains or all origins to access
Puter for ideal LAN or VPN configurations.

doc/self-hosters/domains.md

@@ -6,6 +6,19 @@
 
 Ensure the hosting device has a static IP address to prevent potential connectivity issues due to IP changes. This setup will enable seamless access to Puter and its services across your local network.
 
+### Using `nip.io`
+
+We recommend this configuration for LAN setups. All you need to do is set the following
+at root level in your configuration file:
+
+```json
+  "allow_nipio_domains": true
+```
+
+Puter requires multiple origins to work correctly. `nip.io` is a wildcard DNS for IP addresses,
+so Puter can still have multiple subdomains and you don't need to configure your own DNS or
+hosts file.
+
 ### Using Hosts Files
 
 The hosts file is a straightforward way to map domain names to IP addresses on individual devices. It's simple to set up but requires manual changes on each device that needs access to the domains.

src/backend/src/modules/web/WebServerService.js

@@ -449,13 +449,22 @@ class WebServerService extends BaseService {
                 'at.' + config.static_hosting_domain.toLowerCase(),
             ];
 
+            if ( config.allow_nipio_domains ) {
+                allowedDomains.push('nip.io');
+            }
+
             // Retrieve the Host header and ensure it's in a valid format
             const hostHeader = req.headers.host;
 
-            if (!hostHeader) {
+            if ( ! config.allow_no_host_header && ! hostHeader ) {
                 return res.status(400).send('Missing Host header.');
             }
 
+            if ( config.allow_all_host_values ) {
+                next();
+                return;
+            }
+
             // Parse the Host header to isolate the hostname (strip out port if present)
             const hostName = hostHeader.split(':')[0].trim().toLowerCase();