feat: complete session preferences and PAM fixture gates

README.md

@@ -10,8 +10,11 @@ Latchd is written in Rust. The old Go prototype is kept in `legacy/go/` for refe
 - Shows password, account-expiry, locked-account, and faillock status without replacing PAM's decision.
 - Runs PAM password changes for accounts that require a new password before login.
 - Lets you switch users and sessions without leaving the login screen.
+- Remembers each account's last successful session choice in a root-owned state file.
 - Finds X11 and Wayland desktop entries and can include a TTY shell.
 - Starts sessions with a cleared, explicit environment and drops privileges before running the user process.
+- Registers the selected desktop, session type, seat, and VT with PAM/logind,
+  then imports only approved PAM runtime values into the user session.
 - Records user sessions with UTMPX when the platform provides it.
 - Provides a Ratatui TUI with filtering, keyboard help, refresh, notifications, wallpaper, and reduced-motion support.
 - Runs safely in preview mode for UI work and configuration checks.
@@ -72,7 +75,8 @@ The complete example is in [`extra/config.toml`](extra/config.toml). Important s
 
 - `[accounts]` controls NSS discovery, the faillock helper, faillock policy, and `/etc/shadow` account-age checks.
 - `[x11]` and `[wayland]` select desktop-entry and administrator script directories.
-- `[environment_switcher]` controls session choices and the optional TTY shell.
+- `[environment_switcher]` controls session choices, the optional TTY shell,
+  and the owner-checked last-session preference file.
 - `[visual]` controls wallpaper size, animation, notifications, and reduced motion.
 - `[power_controls]` contains absolute program paths and argv arrays. Commands are never passed through a shell.
 
@@ -107,6 +111,7 @@ make check
 make audit
 make docker-test
 make integration-test
+make pam-fixture-test  # runs when root is available; otherwise reports SKIP
 make system-e2e
 ```