Add thv skill sync: restore project skills from the lock file

cmd/thv/app/skill_helpers.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	tclient "github.com/stacklok/toolhive/pkg/client"
 	"github.com/stacklok/toolhive/pkg/skills"
 	skillclient "github.com/stacklok/toolhive/pkg/skills/client"
 )
@@ -65,3 +66,18 @@ func validateProjectRootForScope(scopeVar, projectRootVar *string) func(*cobra.C
 		return nil
 	}
 }
+
+// resolveProjectRoot returns explicit if set, otherwise auto-detects the
+// project root by walking up from the current directory looking for .git —
+// used by commands (sync, upgrade) that operate on "the project you're in"
+// rather than requiring --project-root on every invocation.
+func resolveProjectRoot(explicit string) (string, error) {
+	if explicit != "" {
+		return explicit, nil
+	}
+	root, err := tclient.DetectProjectRoot("")
+	if err != nil {
+		return "", fmt.Errorf("detecting project root: %w (use --project-root to specify it explicitly)", err)
+	}
+	return root, nil
+}

cmd/thv/app/skill_sync.go

@@ -0,0 +1,124 @@
+// SPDX-FileCopyrightText: Copyright 2025 Stacklok, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+package app
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"github.com/stacklok/toolhive/pkg/skills"
+)
+
+var (
+	skillSyncProjectRoot string
+	skillSyncClientsRaw  string
+	skillSyncCheck       bool
+	skillSyncAdopt       bool
+	skillSyncPrune       bool
+	skillSyncFormat      string
+)
+
+var skillSyncCmd = &cobra.Command{
+	Use:   "sync",
+	Short: "Restore project skills to match the lock file",
+	Long: `Restore a project's installed skills to match toolhive.lock.yaml.
+
+Missing or drifted skills are reinstalled at their pinned digest. Use
+--check to report drift without installing anything (suitable for CI).
+Use --adopt to record lock entries for existing unmanaged installs, and
+--prune to remove installs no longer present in the lock file.`,
+	PreRunE: chainPreRunE(
+		ValidateFormat(&skillSyncFormat),
+	),
+	RunE: skillSyncCmdFunc,
+}
+
+func init() {
+	skillCmd.AddCommand(skillSyncCmd)
+
+	skillSyncCmd.Flags().StringVar(&skillSyncProjectRoot, "project-root", "",
+		"Project root path (default: auto-detected from the current directory)")
+	skillSyncCmd.Flags().StringVar(&skillSyncClientsRaw, "clients", "",
+		`Comma-separated target client apps (e.g. claude-code,opencode), or "all" for every available client`)
+	skillSyncCmd.Flags().BoolVar(&skillSyncCheck, "check", false,
+		"Report drift without installing, writing, or removing anything")
+	skillSyncCmd.Flags().BoolVar(&skillSyncAdopt, "adopt", false,
+		"Write lock entries for existing unmanaged project-scope installs")
+	skillSyncCmd.Flags().BoolVar(&skillSyncPrune, "prune", false,
+		"Remove installs no longer present in the lock file")
+	AddFormatFlag(skillSyncCmd, &skillSyncFormat)
+}
+
+func skillSyncCmdFunc(cmd *cobra.Command, _ []string) error {
+	projectRoot, err := resolveProjectRoot(skillSyncProjectRoot)
+	if err != nil {
+		return err
+	}
+
+	c := newSkillClient(cmd.Context())
+	result, err := c.Sync(cmd.Context(), skills.SyncOptions{
+		ProjectRoot: projectRoot,
+		Clients:     parseSkillInstallClients(skillSyncClientsRaw),
+		Check:       skillSyncCheck,
+		Adopt:       skillSyncAdopt,
+		Prune:       skillSyncPrune,
+	})
+	if err != nil {
+		return formatSkillError("sync skills", err)
+	}
+
+	return printSyncResult(result, skillSyncFormat)
+}
+
+func printSyncResult(result *skills.SyncResult, format string) error {
+	if format == FormatJSON {
+		data, err := json.MarshalIndent(result, "", "  ")
+		if err != nil {
+			return fmt.Errorf("failed to marshal JSON: %w", err)
+		}
+		fmt.Println(string(data))
+		return nil
+	}
+
+	printSkillNameGroup("Installed", result.Installed)
+	printSkillNameGroup("Drifted", result.Drifted)
+	printSkillNameGroup("Missing (not installed)", result.Missing)
+	printSkillNameGroup("Up to date", result.AlreadyCurrent)
+	printSkillNameGroup("Never managed (use --adopt to record)", result.NeverManaged)
+	printSkillNameGroup("Removed from lock (use --prune to remove)", result.RemovedFromLock)
+	printSkillNameGroup("Pruned", result.Pruned)
+	if len(result.Failed) > 0 {
+		fmt.Println("Failed:")
+		for _, f := range result.Failed {
+			fmt.Printf("  %s [%s]: %s\n", f.Name, f.Reason, f.Error)
+		}
+	}
+	if isSyncResultEmpty(result) {
+		fmt.Println("Nothing to sync — the project matches its lock file")
+	}
+	return nil
+}
+
+func printSkillNameGroup(label string, names []string) {
+	if len(names) == 0 {
+		return
+	}
+	fmt.Printf("%s:\n", label)
+	for _, name := range names {
+		fmt.Printf("  %s\n", name)
+	}
+}
+
+func isSyncResultEmpty(result *skills.SyncResult) bool {
+	return len(result.Installed) == 0 &&
+		len(result.Drifted) == 0 &&
+		len(result.Missing) == 0 &&
+		len(result.AlreadyCurrent) == 0 &&
+		len(result.NeverManaged) == 0 &&
+		len(result.RemovedFromLock) == 0 &&
+		len(result.Pruned) == 0 &&
+		len(result.Failed) == 0
+}