fix doctor config-syntax check (dry-build) and diff exit propagation; golden enables flakes + nixpkgs-fmt + pinned nixpkgs registry; v3.0.2

@@ -9,7 +9,7 @@99     .name = .nina,1010     // This is a [Semantic Version](https://semver.org/).1111     // In a future version of Zig it will be used for package deduplication.12-    .version = "3.0.1",12+    .version = "3.0.2",1313     // Together with name, this represents a globally unique package1414     // identifier. This field is generated by the Zig toolchain when the1515     // package is first created, and then *never changes*. This allows

@@ -155,10 +155,10 @@155155         const a = std.fmt.parseInt(u32, ctx.args[0], 10) catch current - 1;156156         const b = std.fmt.parseInt(u32, ctx.args[1], 10) catch current;157157         output.diffHeader(a, b, ctx.machine.name);158-        _ = try exec.diffClosures(ctx.io, &ctx.machine, ctx.gpa, a, b);158+        if (try exec.diffClosures(ctx.io, &ctx.machine, ctx.gpa, a, b) != 0) return error.ProcessFailed;159159     } else {160160         output.diffHeader(if (prev > 0) prev else current - 1, current, ctx.machine.name);161-        _ = try exec.diffClosures(ctx.io, &ctx.machine, ctx.gpa, if (prev > 0) prev else current - 1, current);161+        if (try exec.diffClosures(ctx.io, &ctx.machine, ctx.gpa, if (prev > 0) prev else current - 1, current) != 0) return error.ProcessFailed;162162     }163163 }164164 

@@ -604,7 +604,7 @@604604 605605     // Check config syntax606606     {607-        const r = try capture(gpa, io, machine, &.{ "sudo", "nixos-rebuild", "build", "--dry-run" });607+        const r = try capture(gpa, io, machine, &.{ "sudo", "nixos-rebuild", "dry-build" });608608         defer gpa.free(r.stdout);609609         defer gpa.free(r.stderr);610610         try checks.append(gpa, .{ .name = "config syntax", .status = if (r.exit_code == 0) .ok else .fail });

@@ -28,7 +28,17 @@2828     vim2929     htop3030     ripgrep31+    nixpkgs-fmt # nina fmt3132   ];33+34+  # nina search/diff/pkg use the new `nix` CLI (flakes). Pin the nixpkgs flake35+  # registry to the local channel path so `nix search nixpkgs` resolves offline36+  # instead of fetching github per disposable overlay.37+  nix.settings.experimental-features = [ "nix-command" "flakes" ];38+  nix.registry.nixpkgs.to = {39+    type = "path";40+    path = pkgs.path;41+  };3242 3343   # Headless driving: autologin root on the serial console so the build/boot3444   # harness can run commands without credentials.