Build aarch64 docker image via single-user Nix

Author: DJTBOT

.github/workflows/docker-image.yml

@@ -10,19 +10,29 @@ permissions:
   contents: read
   packages: write
 
+env:
+  NIX_CONFIG: |
+    experimental-features = nix-command flakes
+    extra-platforms = aarch64-linux
+
 jobs:
   build-and-push:
-    runs-on: ubuntu-24.04-arm64
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Install Nix
+      - name: Install Nix (single-user)
         shell: bash
         run: |
           set -euo pipefail
-          curl -fsSL https://install.determinate.systems/nix | sh -s -- install --no-confirm
-          . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
+          curl -fsSL https://install.determinate.systems/nix | sh -s -- install --no-confirm --no-daemon
+          if [ -f "$HOME/.nix-profile/etc/profile.d/nix.sh" ]; then
+            . "$HOME/.nix-profile/etc/profile.d/nix.sh"
+          else
+            echo "Nix profile not found" >&2
+            exit 1
+          fi
           nix --version
 
       - name: Resolve upstream version
@@ -39,8 +49,8 @@ jobs:
         shell: bash
         run: |
           set -euo pipefail
-          . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
-          nix build .#clawdbot-docker
+          . "$HOME/.nix-profile/etc/profile.d/nix.sh"
+          nix build .#packages.aarch64-linux.clawdbot-docker
 
       - name: Load image
         shell: bash