feat: multi-registry plugin distribution system

cmd/wfctl/main.go

@@ -28,6 +28,7 @@ var commands = map[string]func([]string) error{
 	"compat":   runCompat,
 	"generate": runGenerate,
 	"git":      runGit,
+	"registry": runRegistry,
 }
 
 func usage() {
@@ -57,6 +58,7 @@ Commands:
   compat     Compatibility checking (check: verify config works with current engine)
   generate   Code generation (github-actions: generate CI/CD workflows from config)
   git        Git integration (connect: link to GitHub repo, push: commit and push)
+  registry   Registry management (list, add, remove plugin registry sources)
 
 Run 'wfctl <command> -h' for command-specific help.
 `, version)

cmd/wfctl/multi_registry.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"sort"
+)
+
+// MultiRegistry aggregates multiple RegistrySource instances and resolves
+// plugins across them in priority order.
+type MultiRegistry struct {
+	sources []RegistrySource
+}
+
+// NewMultiRegistry creates a multi-registry from a config. Sources are sorted
+// by priority (lowest number = highest priority).
+func NewMultiRegistry(cfg *RegistryConfig) *MultiRegistry {
+	// Sort by priority
+	sorted := make([]RegistrySourceConfig, len(cfg.Registries))
+	copy(sorted, cfg.Registries)
+	sort.Slice(sorted, func(i, j int) bool {
+		return sorted[i].Priority < sorted[j].Priority
+	})
+
+	sources := make([]RegistrySource, 0, len(sorted))
+	for _, sc := range sorted {
+		switch sc.Type {
+		case "github":
+			sources = append(sources, NewGitHubRegistrySource(sc))
+		default:
+			// Skip unknown types
+			fmt.Fprintf(os.Stderr, "warning: unknown registry type %q for %q, skipping\n", sc.Type, sc.Name)
+		}
+	}
+
+	return &MultiRegistry{sources: sources}
+}
+
+// NewMultiRegistryFromSources creates a multi-registry from pre-built sources (useful for testing).
+func NewMultiRegistryFromSources(sources ...RegistrySource) *MultiRegistry {
+	return &MultiRegistry{sources: sources}
+}
+
+// FetchManifest tries each source in priority order, returning the first successful result.
+func (m *MultiRegistry) FetchManifest(name string) (*RegistryManifest, string, error) {
+	var lastErr error
+	for _, src := range m.sources {
+		manifest, err := src.FetchManifest(name)
+		if err == nil {
+			return manifest, src.Name(), nil
+		}
+		lastErr = err
+	}
+	if lastErr != nil {
+		return nil, "", lastErr
+	}
+	return nil, "", fmt.Errorf("plugin %q not found in any configured registry", name)
+}
+
+// SearchPlugins searches all sources and returns deduplicated results.
+// When the same plugin appears in multiple registries, the higher-priority source wins.
+func (m *MultiRegistry) SearchPlugins(query string) ([]PluginSearchResult, error) {
+	seen := make(map[string]bool)
+	var results []PluginSearchResult
+
+	for _, src := range m.sources {
+		srcResults, err := src.SearchPlugins(query)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "warning: search failed for registry %q: %v\n", src.Name(), err)
+			continue
+		}
+		for _, r := range srcResults {
+			if !seen[r.Name] {
+				results = append(results, r)
+				seen[r.Name] = true
+			}
+		}
+	}
+	return results, nil
+}
+
+// ListPlugins lists all plugins from all sources, deduplicated.
+func (m *MultiRegistry) ListPlugins() ([]string, error) {
+	seen := make(map[string]bool)
+	var names []string
+
+	for _, src := range m.sources {
+		srcNames, err := src.ListPlugins()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "warning: list failed for registry %q: %v\n", src.Name(), err)
+			continue
+		}
+		for _, n := range srcNames {
+			if !seen[n] {
+				names = append(names, n)
+				seen[n] = true
+			}
+		}
+	}
+	return names, nil
+}
+
+// Sources returns the configured registry sources.
+func (m *MultiRegistry) Sources() []RegistrySource {
+	return m.sources
+}