refactor(nix): promote remote-dev/ to nix/ with common/vm/host split

Restructures the Home-Manager profile to support both the Arch host and
the Ubuntu remote-dev VM from the same flake.

  - remote-dev/ → nix/ (hard rename; .chezmoiignore updated)
  - home.nix split into common.nix (shared), vm.nix (Mason runtime
    carve-outs + podman stack), host.nix (gpg scdaemon delegation to
    system pcscd)
  - flake.nix exposes homeConfigurations.{vm,host} via a mkProfile
    helper
  - rj alias in dot_zshrc updated to ~/.local/share/dotfiles/nix
  - bootstrap.sh / justfile updated to use #vm against the new path

The split is behaviour-preserving for the VM: vm.nix + common.nix
together carry the same package set as the previous home.nix.
host.nix is provisioned but not yet wired into bootstrap (phase p8).

Phase 1 of the nix-on-host migration plan.

1 files changed, 49 insertions, 0 deletions

diff --git a/nix/flake.lock b/nix/flake.lock
new file mode 100644
index 0000000..349d5fd
--- /dev/null
+++ b/nix/flake.lock
@@ -0,0 +1,49 @@
+{
+  "nodes": {
+    "home-manager": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1778628724,
+        "narHash": "sha256-VNG6hJ146VEenXcDrB3t6MVnrMx+gtyCWTCDkzOp9Qs=",
+        "owner": "nix-community",
+        "repo": "home-manager",
+        "rev": "6a0bbd6b4720da1c9ce7ebf35ff5c41a82db367a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "ref": "master",
+        "repo": "home-manager",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1778443072,
+        "narHash": "sha256-zi7/fsqM/kFdNuED//4WOCUtezGtKKqRNORjMvfwjnA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "da5ad661ba4e5ef59ba743f0d112cbc30e474f32",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "home-manager": "home-manager",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}