feat: add completion subcommand to generate shell completion scripts for Zsh, Bash, PowerShell, and Fish.

src/cli/program/register.subclis.ts

@@ -227,8 +227,20 @@ const entries: SubCliEntry[] = [
       mod.registerUpdateCli(program);
     },
   },
+  {
+    name: "completion",
+    description: "Generate shell completion script",
+    register: async (program) => {
+      const mod = await import("../completion-cli.js");
+      mod.registerCompletionCli(program);
+    },
+  },
 ];
 
+export function getSubCliEntries(): SubCliEntry[] {
+  return entries;
+}
+
 function removeCommand(program: Command, command: Command) {
   const commands = program.commands as Command[];
   const index = commands.indexOf(command);