feat: 跨平台命令助手 kopsc 初始实现

- 意图命令按 OS/架构、Linux 发行版与容器运行时解析并执行对应底层命令
- 内置 docker.clearsafe、net.ports、pkg.refreshindex
- --dry-run 预览、list/explain/platform/version 辅助命令
- 纯 Go 跨平台构建脚本 scripts/build

internal/registry/registry.go

@@ -0,0 +1,120 @@
+// Package registry holds kopsc's built-in command registry: platform-neutral
+// intents, each with one or more platform-specific variants.
+package registry
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Match constrains a Variant to environments. An empty field means "any".
+// A Variant with a completely empty Match is a generic fallback.
+type Match struct {
+	OS         string   // runtime.GOOS
+	Arch       string   // runtime.GOARCH
+	Distro     string   // exact os-release ID, e.g. "centos"
+	DistroLike []string // os-release ID_LIKE ancestry, e.g. "rhel"
+	Runtime    string   // container runtime required on PATH, e.g. "podman"
+}
+
+// Variant is one concrete implementation of a command.
+type Variant struct {
+	Match Match
+	Argv  []string // program followed by arguments
+	Shell bool     // run through the platform shell instead of exec'ing Argv[0]
+	Note  string   // human-readable rationale shown by `kopsc explain`
+}
+
+// Command is a platform-neutral intent, e.g. "docker.clearsafe".
+type Command struct {
+	ID       string // hierarchical, dot-separated: "docker.clearsafe"
+	Aliases  []string
+	Summary  string
+	Group    string // CLI grouping, e.g. "docker"
+	Action   string // what the command does, including its safety contract
+	Variants []Variant
+}
+
+// Registry is an ordered set of commands.
+type Registry struct {
+	Commands []Command
+}
+
+// Validate reports structural problems: empty or duplicate identifiers,
+// empty aliases, commands without variants and variants without an argv.
+func (r *Registry) Validate() error {
+	seenIDs := make(map[string]bool)
+	seenAliases := make(map[string]string)
+
+	for i, cmd := range r.Commands {
+		if strings.TrimSpace(cmd.ID) == "" {
+			return fmt.Errorf("command #%d: empty ID", i)
+		}
+		if seenIDs[cmd.ID] {
+			return fmt.Errorf("command #%d: duplicate ID %q", i, cmd.ID)
+		}
+		seenIDs[cmd.ID] = true
+
+		if strings.TrimSpace(cmd.Summary) == "" {
+			return fmt.Errorf("command %q: empty summary", cmd.ID)
+		}
+		if len(cmd.Variants) == 0 {
+			return fmt.Errorf("command %q: no variants", cmd.ID)
+		}
+
+		for _, alias := range cmd.Aliases {
+			if strings.TrimSpace(alias) == "" {
+				return fmt.Errorf("command %q: empty alias", cmd.ID)
+			}
+			if owner, ok := seenAliases[alias]; ok {
+				return fmt.Errorf("command %q: alias %q already used by %q", cmd.ID, alias, owner)
+			}
+			seenAliases[alias] = cmd.ID
+		}
+
+		for j, variant := range cmd.Variants {
+			if len(variant.Argv) == 0 || strings.TrimSpace(variant.Argv[0]) == "" {
+				return fmt.Errorf("command %q variant #%d: empty argv", cmd.ID, j)
+			}
+			if err := variant.Match.validate(); err != nil {
+				return fmt.Errorf("command %q variant #%d: %w", cmd.ID, j, err)
+			}
+		}
+	}
+
+	return nil
+}
+
+func (m Match) validate() error {
+	for _, field := range m.DistroLike {
+		if strings.TrimSpace(field) == "" {
+			return fmt.Errorf("empty DistroLike entry")
+		}
+	}
+	return nil
+}
+
+// Lookup finds a command by ID or alias.
+func (r *Registry) Lookup(idOrAlias string) (*Command, bool) {
+	for i := range r.Commands {
+		cmd := &r.Commands[i]
+		if cmd.ID == idOrAlias {
+			return cmd, true
+		}
+		for _, alias := range cmd.Aliases {
+			if alias == idOrAlias {
+				return cmd, true
+			}
+		}
+	}
+	return nil, false
+}
+
+// IDs returns every command ID in registry order.
+func (r *Registry) IDs() []string {
+	ids := make([]string, 0, len(r.Commands))
+	for _, cmd := range r.Commands {
+		ids = append(ids, cmd.ID)
+	}
+	return ids
+}