feat: complete session preferences and PAM fixture gates

legacy/go/session/env.go

@@ -1,6 +1,3 @@
-// session — environment variable setup for latchd sessions.
-//
-// Mirrors vendor/src/post_login/env_variables.rs.
 package session
 
 import (

legacy/go/session/exec.go

@@ -1,6 +1,3 @@
-// session — process execution and session spawning.
-//
-// Mirrors vendor/src/post_login/mod.rs and wait_with_log.rs.
 package session
 
 import (

legacy/go/session/scan.go

@@ -1,7 +1,3 @@
-// session — environment scanning from xsessions, wayland-sessions,
-// and custom script directories. Includes desktop entry parser.
-//
-// Mirrors vendor/src/post_login/mod.rs:get_envs and parse_desktop_entry.
 package session
 
 import (

legacy/go/session/wayland.go

@@ -1,4 +1 @@
 package session
-
-// Wayland session spawning is handled in exec.go/spawnWayland.
-// This file exists for future Wayland-specific compositor logic.

legacy/go/session/x11.go

@@ -1,6 +1,3 @@
-// session — X11 server setup.
-//
-// Mirrors vendor/src/post_login/x.rs:setup_x.
 package session
 
 import (
@@ -47,7 +44,7 @@ func setupX(uid, gid uint32, groups []uint32, cfg *config.Config) (*exec.Cmd, er
 		dd = "0" + dd
 	}
 
-	// Ignore SIGUSR1 so Xorg sends it when ready.
+	// Xorg sends SIGUSR1 only if the parent ignores it during startup.
 	signal.Ignore(syscall.SIGUSR1)
 
 	cmd := exec.Command(cfg.SystemShell, "-c",