feat: emit Claude Code plugin hint from CLI

cmd/root.go

@@ -193,6 +193,9 @@ func Execute() {
 	if err != nil {
 		fmt.Fprintln(utils.GetDebugLogger(), err)
 	}
+	if hint := utils.SuggestClaudePlugin(); hint != "" {
+		fmt.Fprintln(os.Stderr, hint)
+	}
 	if semver.Compare(version, "v"+utils.Version) > 0 {
 		fmt.Fprintln(os.Stderr, suggestUpgrade(version))
 	}

internal/login/login.go

@@ -172,6 +172,9 @@ func Run(ctx context.Context, stdout io.Writer, params RunParams) error {
 		}
 		handleTelemetryAfterLogin(ctx, params)
 		fmt.Println(loggedInMsg)
+		if hint := utils.SuggestClaudePlugin(); hint != "" {
+			fmt.Fprintln(os.Stderr, hint)
+		}
 		return nil
 	}
 
@@ -223,6 +226,9 @@ func Run(ctx context.Context, stdout io.Writer, params RunParams) error {
 
 	fmt.Fprintf(stdout, "Token %s created successfully.\n\n", utils.Bold(params.TokenName))
 	fmt.Fprintln(stdout, loggedInMsg)
+	if hint := utils.SuggestClaudePlugin(); hint != "" {
+		fmt.Fprintln(os.Stderr, hint)
+	}
 
 	return nil
 }

internal/utils/agent/agent.go

@@ -5,6 +5,11 @@ import (
 	"strings"
 )
 
+// IsClaudeCode reports whether the CLI is running inside Claude Code.
+func IsClaudeCode() bool {
+	return os.Getenv("CLAUDECODE") != "" || os.Getenv("CLAUDE_CODE") != ""
+}
+
 // IsAgent checks environment variables to detect if the CLI is being invoked
 // by an AI coding agent. Based on the detection logic from Vercel's
 // @vercel/functions/ai package.
@@ -37,7 +42,7 @@ func IsAgent() bool {
 		return true
 	}
 	// Claude Code
-	if os.Getenv("CLAUDECODE") != "" || os.Getenv("CLAUDE_CODE") != "" {
+	if IsClaudeCode() {
 		return true
 	}
 	// Replit

internal/utils/misc.go

@@ -17,6 +17,7 @@ import (
 	"github.com/go-git/go-git/v5/plumbing/format/gitignore"
 	"github.com/spf13/afero"
 	"github.com/spf13/viper"
+	"github.com/supabase/cli/internal/utils/agent"
 	"github.com/supabase/cli/pkg/migration"
 )
 
@@ -38,6 +39,15 @@ func ShortContainerImageName(imageName string) string {
 
 const SuggestDebugFlag = "Try rerunning the command with --debug to troubleshoot the error."
 
+const claudeCodeHint = `<claude-code-hint v="1" type="plugin" value="supabase@claude-plugins-official" />`
+
+func SuggestClaudePlugin() string {
+	if agent.IsClaudeCode() {
+		return claudeCodeHint
+	}
+	return ""
+}
+
 var (
 	CmdSuggestion string
 	CurrentDirAbs string