fix(cli): do not pass PLAYWRIGHT_CLI_SESSION as daemon --endpoint

PLAYWRIGHT_CLI_SESSION is the env-var equivalent of -s/--session
(the session name). It is already consumed as such in startDaemon
via resolveSessionName. The leftover else-if branch additionally
re-passed it as the daemon's --endpoint= argument when mode is
'attach', which made the daemon try to connect to a socket at the
literal session-name path.

Repro:
  PLAYWRIGHT_CLI_SESSION=myname playwright-cli attach --cdp=http://127.0.0.1:99999
  -> Error: Daemon pid=...: connect ENOENT myname

The fallback dates back to #39650, when PLAYWRIGHT_CLI_SESSION
only meant "endpoint to attach to". After #39707 it gained its
current session-name meaning, but the obsolete fallback survived
through the --attach -> --endpoint rename (#39972) and the
mode-guard refactor (#40176).

Fixes microsoft/playwright-cli#414

Author: Skn0tt

packages/playwright-core/src/tools/cli-client/session.ts

@@ -139,8 +139,6 @@ export class Session {
       args.push(`--cdp=${cliArgs.cdp}`);
     if (cliArgs.endpoint)
       args.push(`--endpoint=${cliArgs.endpoint}`);
-    else if (mode === 'attach' && process.env.PLAYWRIGHT_CLI_SESSION)
-      args.push(`--endpoint=${process.env.PLAYWRIGHT_CLI_SESSION}`);
 
     const child = spawn(process.execPath, args, {
       detached: true,

tests/mcp/cli-cdp.spec.ts

@@ -57,6 +57,12 @@ test('attach via cdp URL keeps the default session', async ({ cdpServer, cli, se
   expect(listOutput).toContain('(attached)');
 });
 
+test('attach via cdp URL honors PLAYWRIGHT_CLI_SESSION as session name', { annotation: { type: 'issue', description: 'https://github.com/microsoft/playwright-cli/issues/414' } }, async ({ cdpServer, cli }) => {
+  await cdpServer.start();
+  const { exitCode } = await cli('attach', `--cdp=${cdpServer.endpoint}`, { env: { PLAYWRIGHT_CLI_SESSION: 'myname' } });
+  expect(exitCode).toBe(0);
+});
+
 test('detach tears down an attached session', async ({ cdpServer, cli }) => {
   await cdpServer.start();