fix(outbounds): prevent freedom save crash, complete its fields (#4686)

freedomToWire called Object.entries(s.fragment), but getFieldsValue(true)
returns freedom settings without a fragment object when the Fragment switch
is off (its sub-fields never register). That threw 'Cannot convert undefined
or null to object' and silently killed the save. Guard fragment with a
fallback so an unset value is treated as empty.

While verifying against xray-core's freedom config, also:
- add the missing userLevel field (schema, form schema, adapter, UI)
- fix noise applyTo enum to ip/ipv4/ipv6 (xray rejects the old host/all)

Closes #4686

frontend/src/schemas/forms/outbound-form.ts

@@ -166,6 +166,7 @@ export type FreedomFinalRuleForm = z.infer<typeof FreedomFinalRuleFormSchema>;
 export const FreedomOutboundFormSettingsSchema = z.object({
   domainStrategy: z.union([OutboundDomainStrategySchema, z.literal('')]).default(''),
   redirect: z.string().default(''),
+  userLevel: z.number().int().min(0).default(0),
   proxyProtocol: z.number().int().min(0).max(2).default(0),
   fragment: FreedomFragmentSchema.default({
     packets: '1-3',