fix(ci): explicit ASCII encoding for version read, git checkout main

- Force ASCII output encoding in PowerShell to avoid hidden chars
- Add git checkout main before commit to avoid detached HEAD
- Simplify version reading command

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Jenkinsfile

@@ -50,36 +50,31 @@ pipeline {
         stage('Resolve Versions') {
             steps {
                 script {
-                    // Read version using Groovy to avoid PowerShell encoding issues
-                    def props = readProperties file: 'gradle.properties'
-                    def currentVer = props['PUBLISH_VERSION'] ?: '0.1.0'
+                    // Read version using powershell with explicit encoding
+                    def verLine = bat(
+                        script: '@powershell -NoProfile -Command "[Console]::OutputEncoding=[Text.Encoding]::ASCII; (Get-Content gradle.properties | Select-String \'PUBLISH_VERSION\').ToString().Split(\'=\')[1].Trim()"',
+                        returnStdout: true
+                    ).trim()
+                    def currentVer = verLine ?: '0.1.0'
                     echo "Current PUBLISH_VERSION: ${currentVer}"
 
                     def parts = currentVer.tokenize('.')
                     while (parts.size() < 3) { parts.add('0') }
+                    def major = parts[0].toInteger()
+                    def minor = parts[1].toInteger()
+                    def patch = parts[2].toInteger()
+
                     switch (params.VERSION_BUMP) {
-                        case 'major':
-                            parts[0] = (parts[0].toInteger() + 1).toString()
-                            parts[1] = '0'
-                            parts[2] = '0'
-                            break
-                        case 'minor':
-                            parts[1] = (parts[1].toInteger() + 1).toString()
-                            parts[2] = '0'
-                            break
-                        case 'patch':
-                        default:
-                            parts[2] = (parts[2].toInteger() + 1).toString()
-                            break
+                        case 'major': major++; minor = 0; patch = 0; break
+                        case 'minor': minor++; patch = 0; break
+                        case 'patch': default: patch++; break
                     }
-                    def newVer = parts.join('.')
+                    def newVer = "${major}.${minor}.${patch}"
                     echo "Auto-bumped PUBLISH_VERSION: ${currentVer} → ${newVer}"
                     env.NEW_VERSION = newVer
 
-                    // Write back using Groovy to avoid PowerShell encoding issues
-                    def content = readFile('gradle.properties')
-                    content = content.replaceAll(/(?m)^PUBLISH_VERSION=.*/, "PUBLISH_VERSION=${newVer}")
-                    writeFile file: 'gradle.properties', text: content
+                    // Write back using powershell
+                    bat "powershell -Command \"(Get-Content gradle.properties) -replace '^PUBLISH_VERSION=.*', 'PUBLISH_VERSION=${newVer}' | Set-Content -NoNewline gradle.properties\""
 
                     def modules = env.PUBLISH_MODULES.split(',').toList()
                     def versionMap = [:]
@@ -120,6 +115,7 @@ pipeline {
             steps {
                 script {
                     bat """
+                        git checkout main
                         git config user.email "jenkins@xuqm.com"
                         git config user.name "Jenkins CI"
                         git add gradle.properties