laptop image tiers, devshell, partition preserve, cleanup

Images:
- laptopUpstream: bare OS install with AHCI, no templates
- laptopSlim: essentials only (debloat, registry tweaks)
- laptop: full (essentials + all apps)
- win10/win11 images use rec for self-references

CLI:
- preserve recovery partition (4) during disk copy
- expand partition 3 up to partition 4 boundary
- remove VNC CLI flag (use vncDisplay in nix configs instead)

Flake:
- add devShell with vmix alias and PS1 prompt

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

flake.nix

@@ -27,5 +27,20 @@
       type = "app";
       program = "${self.packages.${system}.default}/bin/vmix";
     };
+
+    devShells.${system}.default = pkgs.mkShell {
+      shellHook = ''
+        # vmix CLI available as local flake
+        export VMIX_FLAKE="path:$PWD"
+        alias vmix='nix run "$VMIX_FLAKE" --'
+
+        # bash prompt
+        PROMPT_COMMAND='PS1_CMD1=$(git branch --show-current 2>/dev/null)'; PS1='\[\e[1;7m\]$?\[\e[0m\] \[\e[2m\]\A\[\e[0m\] \[\e[91m\]\u@\h\[\e[0m\] \[\e[92;1m\]\w\[\e[0m\] \[\e[96m\]''${PS1_CMD1}\[\e[0m\] \[\e[1;2m\]$\[\e[0;1m\] \[\e[0m\]'
+      '';
+      buildInputs = with pkgs; [
+        bashInteractive
+        git
+      ];
+    };
   };
 }