feat: 10 funciones infra Docker y 2 tipos — operaciones de contenedores e imagenes

Funciones Docker: list/start/stop/remove containers, list/pull/remove images,
inspect, logs, run. Tipos: ContainerInfo e ImageInfo. Pre-existentes en el
dominio infra, ahora registrados.

functions/infra/docker_list_containers.go

@@ -0,0 +1,104 @@
+package infra
+
+import (
+	"encoding/json"
+	"fmt"
+	"os/exec"
+)
+
+// DockerListContainers lista contenedores Docker. Si all es true, incluye los detenidos.
+func DockerListContainers(all bool) ([]ContainerInfo, error) {
+	args := []string{"ps", "--format", "{{json .}}", "--no-trunc"}
+	if all {
+		args = append(args, "-a")
+	}
+
+	out, err := exec.Command("docker", args...).Output()
+	if err != nil {
+		return nil, fmt.Errorf("docker ps: %w", err)
+	}
+
+	if len(out) == 0 {
+		return nil, nil
+	}
+
+	var containers []ContainerInfo
+	for _, line := range splitLines(out) {
+		if len(line) == 0 {
+			continue
+		}
+		var raw struct {
+			ID      string `json:"ID"`
+			Names   string `json:"Names"`
+			Image   string `json:"Image"`
+			Status  string `json:"Status"`
+			State   string `json:"State"`
+			Ports   string `json:"Ports"`
+			Created string `json:"CreatedAt"`
+			Labels  string `json:"Labels"`
+		}
+		if err := json.Unmarshal(line, &raw); err != nil {
+			continue
+		}
+		containers = append(containers, ContainerInfo{
+			ID:      raw.ID[:12],
+			Name:    raw.Names,
+			Image:   raw.Image,
+			Status:  raw.Status,
+			State:   raw.State,
+			Ports:   raw.Ports,
+			Created: raw.Created,
+			Labels:  parseLabels(raw.Labels),
+		})
+	}
+
+	return containers, nil
+}
+
+// splitLines divide bytes en líneas individuales.
+func splitLines(data []byte) [][]byte {
+	var lines [][]byte
+	start := 0
+	for i, b := range data {
+		if b == '\n' {
+			lines = append(lines, data[start:i])
+			start = i + 1
+		}
+	}
+	if start < len(data) {
+		lines = append(lines, data[start:])
+	}
+	return lines
+}
+
+// parseLabels convierte "key=val,key2=val2" en map.
+func parseLabels(s string) map[string]string {
+	m := make(map[string]string)
+	if s == "" {
+		return m
+	}
+	for _, part := range splitByComma(s) {
+		for i := 0; i < len(part); i++ {
+			if part[i] == '=' {
+				m[part[:i]] = part[i+1:]
+				break
+			}
+		}
+	}
+	return m
+}
+
+func splitByComma(s string) []string {
+	var parts []string
+	start := 0
+	for i := 0; i < len(s); i++ {
+		if s[i] == ',' {
+			parts = append(parts, s[start:i])
+			start = i + 1
+		}
+	}
+	if start < len(s) {
+		parts = append(parts, s[start:])
+	}
+	return parts
+}