feat(client): config search chain, --repo zero-config override, actionable missing-config error

sync/status now resolve the work repository from a fallback chain:
--repo flag > --config flag > AGENT_LIB_CONFIG env > user-level config
(XDG / AppData) > admin platform default. --repo works without any
config file; tokens fall back to AGENT_LIB_GIT_TOKEN/AGENT_LIB_GIT_USER
without ever overriding a configured token. A completely empty chain
yields an error listing every searched location, a minimal config
example and the --repo shortcut.

Closes beads: agent-lib-9o8

internal/cli/status.go

@@ -10,7 +10,7 @@ import (
 )
 
 func newStatusCmd() *cobra.Command {
-	var configPath string
+	var configPath, repoURL, ref string
 	var asJSON bool
 	cmd := &cobra.Command{
 		Use:   "status",
@@ -20,7 +20,8 @@ func newStatusCmd() *cobra.Command {
 			"agent-lib version is included in the report.",
 		Args: cobra.NoArgs,
 		RunE: func(cmd *cobra.Command, args []string) error {
-			report, err := client.Status(client.SyncOptions{ConfigPath: configPath})
+			opts := client.SyncOptions{ConfigPath: configPath, RepoURL: repoURL, Ref: ref}
+			report, err := client.Status(opts)
 			if err != nil {
 				return fmt.Errorf("status: %w", err)
 			}
@@ -37,7 +38,9 @@ func newStatusCmd() *cobra.Command {
 			return nil
 		},
 	}
-	cmd.Flags().StringVar(&configPath, "config", "", "client config path (default: "+client.ConfigEnv+" env or platform default)")
+	cmd.Flags().StringVar(&configPath, "config", "", "client config path (default: "+client.ConfigEnv+" env, user config, or platform default)")
+	cmd.Flags().StringVar(&repoURL, "repo", "", "work repository URL or path — overrides any config, works without one")
+	cmd.Flags().StringVar(&ref, "ref", "", "branch or tag to pull (requires --repo)")
 	cmd.Flags().BoolVar(&asJSON, "json", false, "machine-readable output")
 	return cmd
 }