vcontainer: add auto-start daemon with idle timeout

Add automatic daemon startup and idle timeout cleanup for vdkr/vpdmn:

- vmemres daemon auto-starts on first command (no manual start needed)
- Daemon auto-stops after idle timeout (default: 30 minutes)
- --no-daemon flag for ephemeral mode (single-shot QEMU)
- New config keys: idle-timeout, auto-daemon

Changes:
- vcontainer-init-common.sh: Parse idle_timeout from cmdline, add
  read -t timeout to daemon loop for auto-shutdown
- vrunner.sh: Add --idle-timeout option, pass to kernel cmdline
- vcontainer-common.sh: Auto-start logic in run_runtime_command(),
  --no-daemon flag, config defaults
- container-cross-install.bbclass: Add --no-daemon for explicit
  ephemeral mode during Yocto builds

Configuration:
  vdkr vconfig idle-timeout 3600    # 1 hour timeout
  vdkr vconfig auto-daemon false    # Disable auto-start

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/classes/container-cross-install.bbclass b/classes/container-cross-install.bbclass
index e0fc63da..8137a857 100644
--- a/classes/container-cross-install.bbclass
+++ b/classes/container-cross-install.bbclass
@@ -261,6 +261,7 @@ merge_installed_bundles() {
         local docker_storage="${WORKDIR}/docker-storage-$$.tar"
 
         ${VRUNNER_PATH} \
+            --no-daemon \
             --runtime docker \
             --arch ${BLOB_ARCH} \
             --blob-dir ${VDKR_BLOB_DIR} \
@@ -292,6 +293,7 @@ merge_installed_bundles() {
         local podman_storage="${WORKDIR}/podman-storage-$$.tar"
 
         ${VRUNNER_PATH} \
+            --no-daemon \
             --runtime podman \
             --arch ${BLOB_ARCH} \
             --blob-dir ${VPDMN_BLOB_DIR} \