launcher: add CLAUDE_DISABLE_GPU=1 opt-in (#583)

Mitigation for the Chromium GPU process FATAL exhaustion tracked in
#583. CLAUDE_DISABLE_GPU=1 adds --disable-gpu and
--disable-software-rasterizer to Electron's argv, providing the same
effect as the upstream Settings → disable hardware acceleration toggle
but persistable via the environment.

Co-occurrence with the existing XRDP block does not stack duplicate
flags: a single _disable_gpu sentinel gates the args+= push.

CLAUDE_DISABLE_GPU joins the other CLAUDE_* keys logged by
log_session_env so bug reports include the value.

This is a workaround, not a fix. The underlying Electron/Chromium GPU
process lifecycle issue remains tracked at #583.

Co-Authored-By: Claude <claude@anthropic.com>

scripts/launcher-common.sh

@@ -42,7 +42,8 @@ log_session_env() {
 		QT_IM_MODULE \
 		CLAUDE_USE_WAYLAND \
 		CLAUDE_TITLEBAR_STYLE \
-		CLAUDE_GTK_IM_MODULE
+		CLAUDE_GTK_IM_MODULE \
+		CLAUDE_DISABLE_GPU
 	do
 		log_message "  $key=${!key:-}"
 	done
@@ -140,10 +141,24 @@ build_electron_args() {
 		loginctl show-session "$XDG_SESSION_ID" \
 			-p Type --value 2>/dev/null
 	)
+	# Track GPU-disable decision so XRDP and CLAUDE_DISABLE_GPU don't
+	# stack duplicate flags. Either signal is sufficient.
+	local _disable_gpu=false
 	if [[ -n ${XRDP_SESSION:-} || $rdp_session_type == xrdp ]]; then
-		electron_args+=('--disable-gpu' '--disable-software-rasterizer')
+		_disable_gpu=true
 		log_message 'XRDP session detected - GPU compositing disabled'
 	fi
+	# CLAUDE_DISABLE_GPU=1: opt-in workaround for users hitting the
+	# Chromium GPU process FATAL exhaustion (#583). The same upstream
+	# behaviour is reachable via Settings → disable hardware
+	# acceleration; this lets users persist it via the env without
+	# having to reach the Settings UI through repeated crashes.
+	if [[ ${CLAUDE_DISABLE_GPU:-} == '1' ]]; then
+		_disable_gpu=true
+		log_message 'CLAUDE_DISABLE_GPU=1 - hardware acceleration disabled'
+	fi
+	[[ $_disable_gpu == true ]] \
+		&& electron_args+=('--disable-gpu' '--disable-software-rasterizer')
 
 	# X11 session - no special flags needed
 	if [[ $is_wayland != true ]]; then

tests/launcher-disable-gpu.bats

@@ -0,0 +1,144 @@
+#!/usr/bin/env bats
+#
+# launcher-disable-gpu.bats
+# Tests for the CLAUDE_DISABLE_GPU env var handling in
+# build_electron_args (scripts/launcher-common.sh). The var is an
+# opt-in workaround for the Chromium GPU process FATAL exhaustion
+# tracked in #583. CLAUDE_DISABLE_GPU=1 adds --disable-gpu and
+# --disable-software-rasterizer; co-occurrence with XRDP must not
+# stack duplicate flags.
+#
+
+SCRIPT_DIR="$(cd "$(dirname "${BATS_TEST_FILENAME}")" && pwd)"
+LAUNCHER_COMMON="${SCRIPT_DIR}/../scripts/launcher-common.sh"
+
+setup() {
+	TEST_TMP=$(mktemp -d)
+	export TEST_TMP
+
+	# loginctl shim — same pattern as launcher-xrdp-detection.bats.
+	# Defaults to a non-XRDP session so CLAUDE_DISABLE_GPU is the
+	# only signal in play unless a test overrides MOCK_LOGINCTL_TYPE.
+	mkdir -p "$TEST_TMP/bin"
+	cat > "$TEST_TMP/bin/loginctl" <<'SHIM'
+#!/usr/bin/env bash
+printf '%s\n' "${MOCK_LOGINCTL_TYPE:-x11}"
+SHIM
+	chmod +x "$TEST_TMP/bin/loginctl"
+	export PATH="$TEST_TMP/bin:$PATH"
+
+	log_file="$TEST_TMP/launcher.log"
+	: > "$log_file"
+
+	unset CLAUDE_DISABLE_GPU
+	unset XRDP_SESSION
+	unset XDG_SESSION_ID
+	unset MOCK_LOGINCTL_TYPE
+
+	# shellcheck disable=SC1090
+	source "$LAUNCHER_COMMON"
+
+	is_wayland=false
+	use_x11_on_wayland=true
+}
+
+teardown() {
+	if [[ -n ${TEST_TMP:-} && -d $TEST_TMP ]]; then
+		rm -rf "$TEST_TMP"
+	fi
+}
+
+args_contain() {
+	local needle="$1"
+	local arg
+	for arg in "${electron_args[@]}"; do
+		[[ $arg == "$needle" ]] && return 0
+	done
+	return 1
+}
+
+args_count() {
+	local needle="$1"
+	local arg count=0
+	for arg in "${electron_args[@]}"; do
+		[[ $arg == "$needle" ]] && ((count++))
+	done
+	printf '%d' "$count"
+}
+
+# =============================================================================
+# CLAUDE_DISABLE_GPU=1 — flags must be added
+# =============================================================================
+
+@test "disable-gpu: CLAUDE_DISABLE_GPU=1 adds flags + logs message" {
+	export CLAUDE_DISABLE_GPU=1
+
+	build_electron_args deb
+
+	args_contain '--disable-gpu'
+	args_contain '--disable-software-rasterizer'
+	grep -q 'CLAUDE_DISABLE_GPU=1' "$log_file"
+}
+
+# =============================================================================
+# Co-occurrence with XRDP — no duplicate flags
+# =============================================================================
+
+@test "disable-gpu: with XRDP_SESSION, flags added exactly once (no dup)" {
+	export CLAUDE_DISABLE_GPU=1
+	export XRDP_SESSION=1
+	export XDG_SESSION_ID=5
+	export MOCK_LOGINCTL_TYPE=xrdp
+
+	build_electron_args deb
+
+	[[ "$(args_count '--disable-gpu')" -eq 1 ]]
+	[[ "$(args_count '--disable-software-rasterizer')" -eq 1 ]]
+	# Both signals should still log (independent diagnostic value),
+	# but only one set of flags should reach electron_args.
+	grep -q 'XRDP session detected' "$log_file"
+	grep -q 'CLAUDE_DISABLE_GPU=1' "$log_file"
+}
+
+# =============================================================================
+# Off-states — flags must NOT be added
+# =============================================================================
+
+@test "disable-gpu: unset — flags NOT added" {
+	build_electron_args deb
+
+	run args_contain '--disable-gpu'
+	[[ "$status" -ne 0 ]]
+	run args_contain '--disable-software-rasterizer'
+	[[ "$status" -ne 0 ]]
+}
+
+@test "disable-gpu: empty string — flags NOT added" {
+	export CLAUDE_DISABLE_GPU=''
+
+	build_electron_args deb
+
+	run args_contain '--disable-gpu'
+	[[ "$status" -ne 0 ]]
+}
+
+@test "disable-gpu: =0 — flags NOT added (only literal '1' opts in)" {
+	export CLAUDE_DISABLE_GPU=0
+
+	build_electron_args deb
+
+	run args_contain '--disable-gpu'
+	[[ "$status" -ne 0 ]]
+}
+
+@test "disable-gpu: =true — flags NOT added (no boolean aliases)" {
+	# Documents the strict equality check. If we ever add aliases,
+	# update this test to match. Strict-only matches the existing
+	# CLAUDE_USE_WAYLAND pattern.
+	export CLAUDE_DISABLE_GPU=true
+
+	build_electron_args deb
+
+	run args_contain '--disable-gpu'
+	[[ "$status" -ne 0 ]]
+}