feat: do not display kernel logs with --kernel

SPEC.md

@@ -205,7 +205,7 @@ ecr --kernel /boot/vmlinuz debian -- /bin/sh -c "echo hello"
 4. Launch QEMU with:
    - `-kernel <path>` - provided kernel
    - `-initrd initramfs.cpio.gz` - rootfs as initramfs
-   - `-append "console=ttyS0 rdinit=/bin/sh"` - kernel command line
+   - `-append "console=ttyS0 quiet rdinit=/bin/sh"` - kernel command line
    - `-m <memory>` - memory size (default 2G)
    - `-display none -serial mon:stdio` - console on stdio
    - `-netdev user,id=net0 -device virtio-net-pci,netdev=net0` - network

src/qemu_vm.rs

@@ -56,15 +56,16 @@ pub fn launch_qemu(config: QemuConfig) -> Result<()> {
     // Build kernel command line
     // For initramfs boot, use rdinit= instead of init=
     // No root= needed as initramfs becomes the rootfs
+    // 'quiet' suppresses kernel log messages for a cleaner console
     let kernel_append = if let Some(ref cmd) = config.command {
         let cmd_str = cmd.join(" ");
         format!(
-            "console=ttyS0 rdinit=/bin/sh -- -c \"{}\"",
+            "console=ttyS0 quiet rdinit=/bin/sh -- -c \"{}\"",
             cmd_str
         )
     } else {
         // Default to interactive shell
-        "console=ttyS0 rdinit=/bin/sh".to_string()
+        "console=ttyS0 quiet rdinit=/bin/sh".to_string()
     };
 
     veprintln!("Launching QEMU: {}", qemu_bin);