feat(capabilities): Add Linux distro detection and suggested labels

- Add DistroInfo struct to detect Linux distribution from /etc/os-release
- Add detectLinuxDistro() function to parse distro ID, version, pretty name
- Add generateSuggestedLabels() to create industry-standard labels
- Suggested labels include: linux/windows/macos, distro name, with -latest suffix

🤖 Generated with Claude Code

internal/pkg/envcheck/capabilities.go

@@ -4,8 +4,10 @@
 package envcheck
 
 import (
+	"bufio"
 	"context"
 	"encoding/json"
+	"os"
 	"os/exec"
 	"runtime"
 	"strings"
@@ -23,10 +25,18 @@ type DiskInfo struct {
 	UsedPercent float64 `json:"used_percent"`
 }
 
+// DistroInfo holds Linux distribution information
+type DistroInfo struct {
+	ID         string `json:"id,omitempty"`          // e.g., "ubuntu", "debian", "fedora"
+	VersionID  string `json:"version_id,omitempty"`  // e.g., "24.04", "12"
+	PrettyName string `json:"pretty_name,omitempty"` // e.g., "Ubuntu 24.04 LTS"
+}
+
 // RunnerCapabilities represents the capabilities of a runner for AI consumption
 type RunnerCapabilities struct {
 	OS               string              `json:"os"`
 	Arch             string              `json:"arch"`
+	Distro           *DistroInfo         `json:"distro,omitempty"`
 	Docker           bool                `json:"docker"`
 	DockerCompose    bool                `json:"docker_compose"`
 	ContainerRuntime string              `json:"container_runtime,omitempty"`
@@ -36,6 +46,7 @@ type RunnerCapabilities struct {
 	Limitations      []string            `json:"limitations,omitempty"`
 	Disk             *DiskInfo           `json:"disk,omitempty"`
 	Bandwidth        *BandwidthInfo      `json:"bandwidth,omitempty"`
+	SuggestedLabels  []string            `json:"suggested_labels,omitempty"`
 }
 
 // CapabilityFeatures represents feature support flags
@@ -65,6 +76,11 @@ func DetectCapabilities(ctx context.Context, dockerHost string) *RunnerCapabilit
 		},
 	}
 
+	// Detect Linux distribution
+	if runtime.GOOS == "linux" {
+		cap.Distro = detectLinuxDistro()
+	}
+
 	// Detect Docker
 	cap.Docker, cap.ContainerRuntime = detectDocker(ctx, dockerHost)
 	if cap.Docker {
@@ -78,9 +94,76 @@ func DetectCapabilities(ctx context.Context, dockerHost string) *RunnerCapabilit
 	// Detect disk space
 	cap.Disk = detectDiskSpace()
 
+	// Generate suggested labels based on detected capabilities
+	cap.SuggestedLabels = generateSuggestedLabels(cap)
+
 	return cap
 }
 
+// detectLinuxDistro reads /etc/os-release to get distribution info
+func detectLinuxDistro() *DistroInfo {
+	file, err := os.Open("/etc/os-release")
+	if err != nil {
+		return nil
+	}
+	defer file.Close()
+
+	distro := &DistroInfo{}
+	scanner := bufio.NewScanner(file)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, "ID=") {
+			distro.ID = strings.Trim(strings.TrimPrefix(line, "ID="), "\"")
+		} else if strings.HasPrefix(line, "VERSION_ID=") {
+			distro.VersionID = strings.Trim(strings.TrimPrefix(line, "VERSION_ID="), "\"")
+		} else if strings.HasPrefix(line, "PRETTY_NAME=") {
+			distro.PrettyName = strings.Trim(strings.TrimPrefix(line, "PRETTY_NAME="), "\"")
+		}
+	}
+
+	if distro.ID == "" {
+		return nil
+	}
+
+	return distro
+}
+
+// generateSuggestedLabels creates industry-standard labels based on capabilities
+func generateSuggestedLabels(cap *RunnerCapabilities) []string {
+	labels := []string{}
+	seen := make(map[string]bool)
+
+	addLabel := func(label string) {
+		if label != "" && !seen[label] {
+			seen[label] = true
+			labels = append(labels, label)
+		}
+	}
+
+	// OS labels
+	switch cap.OS {
+	case "linux":
+		addLabel("linux")
+		addLabel("linux-latest")
+	case "windows":
+		addLabel("windows")
+		addLabel("windows-latest")
+	case "darwin":
+		addLabel("macos")
+		addLabel("macos-latest")
+	}
+
+	// Distro labels (Linux only)
+	if cap.Distro != nil && cap.Distro.ID != "" {
+		distro := strings.ToLower(cap.Distro.ID)
+		addLabel(distro)
+		addLabel(distro + "-latest")
+	}
+
+	return labels
+}
+
 // detectDiskSpace detects disk space on the root filesystem
 func detectDiskSpace() *DiskInfo {
 	var stat unix.Statfs_t