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)}`);

packages/cli/src/commands/dev.ts

@@ -5,6 +5,7 @@ import { resolve, dirname, basename, join } from "node:path";
 import { fileURLToPath } from "node:url";
 import * as clack from "@clack/prompts";
 import { c } from "../ui/colors.js";
+import { isDevMode } from "../utils/env.js";
 
 /**
  * Check if a port is available by trying to listen on it briefly.
@@ -31,19 +32,6 @@ async function findAvailablePort(startPort: number): Promise<number> {
   return startPort; // fallback — let the server fail with a clear error
 }
 
-/**
- * Detect whether we're running from source (monorepo dev) or from the built bundle.
- * When running via tsx from source, the file is at cli/src/commands/dev.ts.
- * When running from the built bundle, the file is at cli/dist/cli.js.
- * We check the filename portion of the URL to avoid false positives from
- * directory names (e.g., /Users/someone/src/...).
- */
-function isDevMode(): boolean {
-  const url = new URL(import.meta.url);
-  // In dev mode the file is a .ts source file; in production it's a bundled .js
-  return url.pathname.endsWith(".ts");
-}
-
 export default defineCommand({
   meta: { name: "dev", description: "Start the studio for local development" },
   args: {