CLI: improve command descriptions in help output (#18486)

* CLI: clarify config vs configure descriptions

* CLI: improve top-level command descriptions

* CLI: make direct command help more descriptive

* CLI: add commands hint to root help

* CLI: show root help hint in implicit help output

* CLI: add help example for command-specific help

* CLI: tweak root subcommand marker spacing

* CLI: mark clawbot as subcommand root in help

* CLI: derive subcommand markers from registry metadata

* CLI: escape help regex CLI name

src/cli/config-cli.ts

@@ -280,7 +280,9 @@ export async function runConfigUnset(opts: { path: string; runtime?: RuntimeEnv
 export function registerConfigCli(program: Command) {
   const cmd = program
     .command("config")
-    .description("Config helpers (get/set/unset). Run without subcommand for the wizard.")
+    .description(
+      "Non-interactive config helpers (get/set/unset). Run without subcommand for the setup wizard.",
+    )
     .addHelpText(
       "after",
       () =>