[IntelliJ] Uncaught Exception Error retrieving vulnerability data from GitHub Security Advisory API java.net.ConnectException

IntelliJ build version: 2025.3.2 IU-253.30387.90
OS: Mac OS X
JDK: JetBrains s.r.o. 21.0.9
Plugin version: 3.97.1-2025.3
Additional Info: None
Parent component:

com.intellij.openapi.wm.impl.IdeRootPane[,0,0,2944x1410,layout=com.intellij.openapi.wm.impl.IdeRootPane$CustomHeaderRootLayout,alignmentX=0.0,alignmentY=0.0,border=,flags=449,maximumSize=,minimumSize=,preferredSize=]

Error message:

IdeaLoggingEvent[message=Error retrieving vulnerability data from GitHub Security Advisory API, throwable=java.net.ConnectException
	at <REDACTED: user-file-path>(HttpClientImpl.java:955)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.CVECheckService.retrieveVulnerabilityData(CVECheckService.java:312)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.CVECheckService.fetchCves(CVECheckService.java:241)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.CVECheckService.getCveUpgradeIssues(CVECheckService.java:200)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.CVECheckService.batchGetCVEIssues(CVECheckService.java:171)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.JavaUpgradeIssuesDetectionService.getCVEIssues(JavaUpgradeIssuesDetectionService.java:385)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service

Start in CVECheckService.java at retrieveVulnerabilityData and trace the calls from fetchCves through batchGetCVEIssues. Reproduce the GitHub Security Advisory API connection failure and determine the expected handling for the ConnectException. Done means the reported failure no longer appears as an uncaught exception and the vulnerability-checking flow has coverage for the failure case.