feat(remote-dev): silence podman cgroups-v1 deprecation warning

Ubuntu 20.04 still defaults to cgroups v1; podman 5 emits a deprecation
warning on every single invocation. Flipping the host to v2 is a reboot
that affects every workload and only matters if we need rootless
--memory/--cpus, so just silence the warning via the documented
PODMAN_IGNORE_CGROUPSV1_WARNING env var on the home-manager side.

2 files changed, 10 insertions, 1 deletions

diff --git a/remote-dev/README.md b/remote-dev/README.md
index 172be80..c6519a5 100644
--- a/remote-dev/README.md
+++ b/remote-dev/README.md
@@ -183,7 +183,9 @@ Verify:
 ```sh
 podman info | grep -E 'cgroupVersion|graphDriverName|networkBackend'
 # expected: graphDriverName: overlay, networkBackend: netavark
-# cgroupVersion: v1 is fine — only blocks --memory/--cpus flags.
+# cgroupVersion: v1 is fine — only blocks --memory/--cpus flags. The
+# podman v5 deprecation warning is silenced by PODMAN_IGNORE_CGROUPSV1_WARNING,
+# set in home.nix.
 podman run --rm docker.io/library/alpine echo hi
 ```
 
diff --git a/remote-dev/home.nix b/remote-dev/home.nix
index 6ba6620..4d5a476 100644
--- a/remote-dev/home.nix
+++ b/remote-dev/home.nix
@@ -14,6 +14,13 @@ in
   home.homeDirectory = builtins.getEnv "HOME";
   home.stateVersion = "25.05";
 
+  home.sessionVariables = {
+    # Ubuntu 20.04 still defaults to cgroups v1; podman 5 warns on every
+    # invocation. Flipping to v2 is a host-level reboot (see README) and
+    # only matters if we need --memory/--cpus, so silence the warning.
+    PODMAN_IGNORE_CGROUPSV1_WARNING = "1";
+  };
+
   # ── Packages ────────────────────────────────────────────────────────────────
   # Policy: this profile carries leaf CLI tools plus editor/AI-agent
   # runtimes (node, uv). It must NEVER carry anything the project build