refactor(cli): address review findings in telemetry code

- Extract shared isDevMode() to utils/env.ts (was duplicated in dev.ts and client.ts)
- Use ui/colors.ts instead of raw ANSI escapes in telemetry notice (respects NO_COLOR)
- Derive known commands from subCommands object instead of maintaining duplicate set
- Skip telemetry on --help/--version and unknown commands
- Gate incrementCommandCount() behind shouldTrack() (no disk writes in CI)
- Add flushSync() for process.exit() paths (beforeExit doesn't fire on explicit exit)
- Remove dead trackBrowserInstall(success) param (failure path never called it)
- Remove redundant isEnabled/anonymousId caching in client.ts (config.ts cache suffices)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/cli/src/commands/browser.ts

@@ -48,7 +48,7 @@ async function runEnsure(): Promise<void> {
   });
 
   downloadSpinner.stop(c.success("Download complete"));
-  trackBrowserInstall(true);
+  trackBrowserInstall();
 
   console.log();
   console.log(`   ${c.dim("Source:")}  ${c.bold(result.source)}`);