initial: Kotlin/Gradle skeleton for cloud-installer

Compiles to a 3.4 MB fat jar via shadow plugin.
Entrypoint with CLI dispatch (pull/push subcommands) + FlatLaf init.
Real sync logic stubbed; lands in subsequent commits per task plan.

Build via containerized gradle (8.10.2 + jdk21) to sidestep the
Kotlin 2.1 + JDK 26 compiler crash. Documented in README.

CI workflow tags-only release artifact upload prepared (needs
RELEASE_TOKEN secret in repo settings before first tag).

src/main/kotlin/center/timemachine/cloud/Cli.kt

@@ -0,0 +1,20 @@
+package center.timemachine.cloud
+
+/**
+ * Subcommand dispatchers. Skeleton — real arg parsing + sync logic lands
+ * in subsequent tasks. For now these print intent and exit cleanly so the
+ * fat jar can be smoke-tested end-to-end through Prism / frazclient.
+ */
+object Cli {
+    fun runPull(args: Array<String>): Int {
+        println("cloud-installer pull: ${args.joinToString(" ")}")
+        println("(not yet implemented; skeleton commit only)")
+        return 0
+    }
+
+    fun runPush(args: Array<String>): Int {
+        println("cloud-installer push: ${args.joinToString(" ")}")
+        println("(not yet implemented; skeleton commit only)")
+        return 0
+    }
+}