CLI daemon socket path silently truncated past sun_path (104 B on macOS) — stale-socket cleanup never fires, session is permanently EADDRINUSE

makeSocketPath(domain, name) (packages/playwright-core/src/server/utils/fileUtils.ts; observed in vendored @playwright/cli 0.1.6 → lib/coreBundle.js:7903-7912) composes os.tmpdir()/pw-<userhash8>/<domain>/<name>.sock with no length guard. For the cli domain, daemonSocketPath() (src/tools/cli-daemon/daemon.ts; lib/coreBundle.js:64634-64636) passes name = <workspaceDirHash16>-<sessionName>. On macOS the default $TMPDIR is /var/folders/xx/…/T (~48 bytes), giving a ~65-byte prefix, and sockaddr_un.sun_path is 104 bytes — so any session name longer than ~17 characters overflows.

libuv silently truncates the path on BOTH bind() and connect() (reproduced on Node 22.10.0 / libuv 1.49.2), so the socket is created at the truncated path and the session initially works. But fs.stat()/fs.unlink() use the untruncated path, so all three cleanup paths miss the file that actually exists:

1. startCliDaemonServer()'s socketExists + unlink stale-socket guard (daemon.ts; coreBundle.js:64557-64563) never fires → server.listen() throws EADDRINUSE;
2. deleteSessionFile()'s unlink(sessionConfig.socketPath) (coreBundle.js:64614-64616) never removes the socket — and swallows the ENOENT;
3. Session._connect()'s error-path unlink (src/tools/cli-client/session.ts; lib/tools/cli-client/session.js:112-118) never removes it either.

Consequences: after any abrupt daemon exit — including playwright-cli kill-all, which SIGKILLs (lib/tools/cli-client/program.js:241) so libuv never unlinks — the socket file survives forever. open -s=<same name> throws Error: listen EADDRINUSE …/<full-name>.sock, printing a path that is not on disk (the on-disk name is truncated and has no .sock suffix), and every later command reports "The browser is not open". Only a manual rm of the truncated path recovers. Two session names sharing a truncated prefix also silently collide on one socket.

Repro (macOS):

S=$(uuidgen)
playwright-cli -s=$S open https://example.com
ls -l "$TMPDIR"/pw-*/cli/    # name is truncated, .sock suffix gone
playwright-cli kill-all
playwright-cli -s=$S open https://example.com   # EADDRINUSE on a path ls cannot find

Suggested fix: in makeSocketPath, when the composed path would exceed sizeof(sun_path) (104 darwin / 108 linux), substitute a digest for the name — e.g. <sha1(name).slice(0,16)>.sock — so the on-disk name stays deterministic and bounded; or throw a clear error naming the limit rather than letting the kernel truncate. Secondary: have startCliDaemonServer catch EADDRINUSE and print an actionable message (with the real on-disk path) instead of a raw Node stack.

Context: we drive playwright-cli from coding agents with per-project session names (UUIDs); this footgun cost multiple debugging sessions before the truncation was spotted.