Merge remote-tracking branch 'origin/main' into pr61/metal-device-fixes

# Conflicts:
#	.github/workflows/source-check.yml

docs/SETUP.md

@@ -73,6 +73,17 @@ opts in to Hyprland-only recovery of a default-prefix Riot session with no
 visible window; it is off by default. See [troubleshooting](TROUBLESHOOTING.md#riot-exits-and-league-reports-that-it-lost-its-connection)
 for the observed failures, recovery guards and NSURLSession limitations.
 
+`RCLOL_FILTER_HOST_ENV=1` opts in to removing host desktop-session variables before
+the guest starts: `WAYLAND_DISPLAY`, `XDG_SESSION_*`, `XDG_CURRENT_DESKTOP`,
+GNOME/KDE/GDM, systemd, SSH agent, terminal, toolkit (`QT_*`, `GTK_*`, `GDK_*`),
+Flatpak/Snap/AppImage and exported shell functions, and `SHELL` becomes `/bin/zsh`.
+It is off by default. Variables that Darling or the host graphics and audio libraries read
+are always kept: `DISPLAY`, `XAUTHORITY`, `XDG_RUNTIME_DIR` and the XDG base directories,
+D-Bus, PulseAudio/PipeWire/ALSA, `DRI_PRIME`, `MESA_*`, `__GL_*`, `__NV_*`, `VK_*`,
+`LD_PRELOAD` and `LD_LIBRARY_PATH`. List names to keep anyway in `RCLOL_KEEP_HOST_ENV`,
+for example `RCLOL_KEEP_HOST_ENV=WAYLAND_DISPLAY`. The launcher always closes inherited
+file descriptors above stderr before the guest starts.
+
 ## Updating an existing runtime
 
 `./scripts/update.sh` updates everything after `git pull`: `build.sh`, then the base install, then `install-runtime.sh`. When a pull changes a patch, `prepare.py` finds the earlier version applied in that component (its copy in `build/applied-patches`, or a version from this repository's history), reverts it, and applies the new one. It never resets a repository; if neither version matches, it stops and names the repository with other edits. The steps below update single components instead.

docs/TESTING.md

@@ -27,7 +27,7 @@ Expected: `METAL_DEVICE_INFO failures=0 pass=1`. It covers how `MTLDevice.name`
 
 The LLVM version check compiles Iridium's actual dynamic loader against small stub libraries. It verifies that a matching major initializes, older/newer majors produce a version mismatch, and a missing library fails initialization. It does not start Darling. The native AIR translator (`python3 tools/build-riot-air-check.py --native`) selects both headers and the shared library from the same `llvm-config`; its build prints those paths so shader results can be attributed to the tested LLVM installation.
 
-The patch check uses temporary base indexes and does not reset or modify the source checkout. The launcher check uses stub commands and never starts or contacts Riot or Darling. It checks installed-client and first-time-installer launches, strips inherited `DYLD_INSERT_LIBRARIES` even with the old VPX opt-in set, and preserves Darling runtime library/framework paths. The memory-installer check imports the installer and exercises its policy (default source is the prepared artifact; the artifact is never a destination of a different library) in temporary directories. The Foundation-installer check does the same for the overlay installer: it seeds a temporary framework from a stub SDK, replaces `Versions/C/Foundation`, keeps the standard symlinks, stages a backup, treats a re-run as current and refuses a non-Mach-O source. The installer handoff mock covers 28 scenarios, including HTTP 409, interrupted verification and preserving active downloads.
+The patch check uses temporary base indexes and does not reset or modify the source checkout. The launcher check uses stub commands and never starts or contacts Riot or Darling. It checks installed-client and first-time-installer launches, strips inherited `DYLD_INSERT_LIBRARIES` even with the old VPX opt-in set, preserves Darling runtime library/framework paths, and checks that host file descriptors the launcher inherited (including multi-digit ones) are closed before the guest starts. The memory-installer check imports the installer and exercises its policy (default source is the prepared artifact; the artifact is never a destination of a different library) in temporary directories. The Foundation-installer check does the same for the overlay installer: it seeds a temporary framework from a stub SDK, replaces `Versions/C/Foundation`, keeps the standard symlinks, stages a backup, treats a re-run as current and refuses a non-Mach-O source. The installer handoff mock covers 28 scenarios, including HTTP 409, interrupted verification and preserving active downloads.
 
 ## NSURLSession lifecycle regression
 
@@ -181,7 +181,7 @@ build/riot-host-receive-check
 python3 tools/riot-launcher-offline-check.py
 ```
 
-Expected: `warm_empty_allocations=0 single_packet_allocations=2`, correct credentials, descriptor ownership/CLOEXEC, sender addresses, multiple batches, truncation flags, callback reentrancy and exception cleanup. The old receive implementation makes 32 allocations for a warmed empty receive and 64 for a single-packet receive in the same fixture. These are allocation counts, not an FPS benchmark. The launcher check uses stub commands and never starts or contacts Riot or Darling. It checks installed-client and first-time-installer launches, strips inherited `DYLD_INSERT_LIBRARIES` even with the old VPX opt-in set, and preserves Darling runtime library/framework paths.
+Expected: `warm_empty_allocations=0 single_packet_allocations=2`, correct credentials, descriptor ownership/CLOEXEC, sender addresses, multiple batches, truncation flags, callback reentrancy and exception cleanup. The old receive implementation makes 32 allocations for a warmed empty receive and 64 for a single-packet receive in the same fixture. These are allocation counts, not an FPS benchmark. The launcher check uses stub commands and never starts or contacts Riot or Darling. It checks installed-client and first-time-installer launches, strips inherited `DYLD_INSERT_LIBRARIES` even with the old VPX opt-in set, preserves Darling runtime library/framework paths, and checks that host file descriptors the launcher inherited (including multi-digit ones) are closed before the guest starts.
 
 The same source passed AddressSanitizer/UndefinedBehaviorSanitizer and leak detection. Allocation counts depend on this fixture/compiler/library; preserve the no-wasted-slot property rather than interpreting them as game performance. See [setup](SETUP.md#updating-an-existing-runtime) for server build/install/activation.