Mac mini support: arm64 cross-build installed beside the binary and pushed by arch; ARM machine name from the device tree

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/metrics/metrics.go

@@ -914,6 +914,12 @@ var cpuModel = func() string {
 			}
 		}
 	}
+	// ARM boards don't put a model name in cpuinfo; the device tree names the machine.
+	for _, p := range []string{"/sys/firmware/devicetree/base/model", "/proc/device-tree/model", "/sys/devices/virtual/dmi/id/product_name"} {
+		if m := strings.TrimRight(strings.TrimSpace(readStr(p)), "\x00"); m != "" {
+			return m
+		}
+	}
 	return ""
 }()
 

internal/nodes/nodes.go

@@ -313,8 +313,13 @@ func (m *Manager) Push(ctx context.Context, name, binPath, ourArch string) PushR
 	_ = json.NewDecoder(io.LimitReader(resp.Body, 64<<10)).Decode(&me)
 	resp.Body.Close()
 	if me.Arch != "" && ourArch != "" && me.Arch != ourArch {
-		res.Error = fmt.Sprintf("architecture mismatch: node is %s, this binary is %s — build for it and deploy by hand", me.Arch, ourArch)
-		return res
+		// look for a sibling build: /usr/local/bin/hamlab-arm64 next to /usr/local/bin/hamlab
+		alt := binPath + "-" + me.Arch
+		if _, err := os.Stat(alt); err != nil {
+			res.Error = fmt.Sprintf("node is %s but only a %s build is installed here (expected %s; run make deploy, which builds it)", me.Arch, ourArch, alt)
+			return res
+		}
+		binPath = alt
 	}
 	f, err := os.Open(binPath)
 	if err != nil {