build: add Kotlin Toolchain migration with Gradle fallback

plugins/github-release/src/GitHubRelease.kt

@@ -0,0 +1,86 @@
+package dev.inmo.kslog.build.release
+
+import org.jetbrains.amper.plugins.ExecutionAvoidance
+import org.jetbrains.amper.plugins.TaskAction
+import java.nio.file.Files
+import java.nio.file.Path
+import kotlin.io.path.deleteIfExists
+import kotlin.io.path.isRegularFile
+import kotlin.io.path.pathString
+import kotlin.io.path.writeText
+
+@TaskAction(ExecutionAvoidance.Disabled)
+fun githubRelease(
+    projectRootDir: String,
+    settings: GitHubReleaseSettings,
+) {
+    val root = Path.of(projectRootDir).toAbsolutePath().normalize()
+    val changelog = root.resolve(settings.changelogFile).normalize()
+    require(changelog.startsWith(root) && changelog.isRegularFile()) {
+        "Changelog must be an existing file inside the module: $changelog"
+    }
+
+    val releasePreflight = root.resolve("verification/check_release_consistency.py")
+    require(releasePreflight.isRegularFile()) { "Missing release consistency preflight: $releasePreflight" }
+    runCommand(root, listOf("python3", releasePreflight.pathString))
+
+    val parser = root.resolve("changelog_parser.sh")
+    require(parser.isRegularFile()) { "Missing changelog parser: $parser" }
+    val notes = runCommand(root, listOf("bash", parser.pathString, settings.version, changelog.pathString))
+        .trim()
+    require(notes.isNotEmpty()) { "No CHANGELOG.md section found for ${settings.version}" }
+
+    val tag = "${settings.tagPrefix}${settings.version}"
+    val targetCommitish = settings.targetCommitish.ifBlank { settings.version }
+    val repository = "${settings.owner}/${settings.repository}"
+    if (System.getenv("KSLOG_GITHUB_RELEASE_DRY_RUN").toBoolean()) {
+        println("Dry run: GitHub release $repository tag=$tag target=$targetCommitish title=${settings.version}")
+        println(notes)
+        return
+    }
+
+    val token = System.getenv("GITHUB_RELEASE_TOKEN")
+        ?: System.getenv("GH_TOKEN")
+        ?: System.getenv("GITHUB_TOKEN")
+        ?: error("Set GITHUB_RELEASE_TOKEN, GH_TOKEN, or GITHUB_TOKEN before creating a release")
+
+    val notesFile = Files.createTempFile("kslog-release-notes-", ".md")
+    try {
+        notesFile.writeText(notes)
+        val process = ProcessBuilder(
+            "gh",
+            "release",
+            "create",
+            tag,
+            "--repo",
+            repository,
+            "--title",
+            settings.version,
+            "--target",
+            targetCommitish,
+            "--notes-file",
+            notesFile.pathString,
+        )
+            .directory(root.toFile())
+            .redirectErrorStream(true)
+        process.environment()["GH_TOKEN"] = token
+        val started = process.start()
+        val output = started.inputStream.bufferedReader().use { it.readText() }
+        val exitCode = started.waitFor()
+        check(exitCode == 0) { "gh release create failed with exit code $exitCode:\n$output" }
+        print(output)
+    } finally {
+        notesFile.deleteIfExists()
+    }
+}
+
+private fun runCommand(workingDirectory: Path, command: List<String>): String {
+    val process = ProcessBuilder(command)
+        .directory(workingDirectory.toFile())
+        .redirectErrorStream(true)
+        .start()
+    val output = process.inputStream.bufferedReader().use { it.readText() }
+    val exitCode = process.waitFor()
+    check(exitCode == 0) { "Command failed with exit code $exitCode: ${command.first()}\n$output" }
+    return output
+}