feat(mosaic): alphabetize and group mosaic --help output (#402)

packages/mosaic/src/cli.ts

@@ -33,7 +33,23 @@ try {
 
 const program = new Command();
 
-program.name('mosaic').description('Mosaic Stack CLI').version(CLI_VERSION);
+program
+  .name('mosaic')
+  .description('Mosaic Stack CLI')
+  .version(CLI_VERSION)
+  .configureHelp({ sortSubcommands: true })
+  .addHelpText(
+    'after',
+    `
+Command Groups:
+
+  Runtime:    tui, login, sessions
+  Gateway:    gateway
+  Framework:  agent, bootstrap, coord, doctor, init, launch, mission, prdy, seq, sync, upgrade, wizard, yolo
+  Platform:   update
+  Runtimes:   claude, codex, opencode, pi
+`,
+  );
 
 // ─── runtime launchers + framework commands ────────────────────────────
 
@@ -214,7 +230,10 @@ program
 
 // ─── sessions ───────────────────────────────────────────────────────────
 
-const sessionsCmd = program.command('sessions').description('Manage active agent sessions');
+const sessionsCmd = program
+  .command('sessions')
+  .description('Manage active agent sessions')
+  .configureHelp({ sortSubcommands: true });
 
 sessionsCmd
   .command('list')