Fix NaN handling in mssfix and tun_mtu validation (#139)

* Initial plan

* fix(ui): Add NaN validation for mssfix and tun_mtu inputs

Co-authored-by: gsanchietti <[email protected]>

* refactor: Store parsed values to avoid redundant parsing

Co-authored-by: gsanchietti <[email protected]>

* fix: Add radix parameter to parseInt calls

Co-authored-by: gsanchietti <[email protected]>

* fix(ui): Add missing error messages for tun_mtu and mssfix validation

Co-authored-by: gsanchietti <[email protected]>

* fix: Add radix parameter to all parseInt calls for consistency

Co-authored-by: gsanchietti <[email protected]>

* Apply suggestion from @gsanchietti

* Apply suggestion from @gsanchietti

* Apply suggestion from @gsanchietti

* Apply suggestion from @gsanchietti

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: gsanchietti <[email protected]>
Co-authored-by: Giacomo Sanchietti <[email protected]>

Author: Copilot

ui/src/views/Settings.vue

@@ -589,14 +589,16 @@ export default {
       }
 
       // validate tun_mtu: minimum 576
-      if (parseInt(this.tun_mtu) < 576) {
+      const tunMtuValue = parseInt(this.tun_mtu, 10);
+      if (isNaN(tunMtuValue) || tunMtuValue < 576) {
         this.error.tun_mtu = this.$t("error.tun_mtu_min");
         this.focusElement("tun_mtu");
         isValidationOk = false;
       }
 
       // validate mssfix: minimum 0
-      if (parseInt(this.mssfix) < 0) {
+      const mssfixValue = parseInt(this.mssfix, 10);
+      if (isNaN(mssfixValue) || mssfixValue < 0) {
         this.error.mssfix = this.$t("error.mssfix_min");
         this.focusElement("mssfix");
         isValidationOk = false;
@@ -699,11 +701,11 @@ export default {
         ovpn_netmask: this.netmask,
         ovpn_cn: this.cn,
         api_user: this.user,
-        loki_retention: parseInt(this.loki_retention),
-        prometheus_retention: parseInt(this.prometheus_retention),
+        loki_retention: parseInt(this.loki_retention, 180),
+        prometheus_retention: parseInt(this.prometheus_retention, 15),
         maxmind_license: this.maxmind_license,
-        tun_mtu: parseInt(this.tun_mtu),
-        mssfix: parseInt(this.mssfix),
+        tun_mtu: parseInt(this.tun_mtu, 1500),
+        mssfix: parseInt(this.mssfix, 1455),
         allowed_ips: this.allowed_ips
           .split("\n")
           .map((ip) => ip.trim())