Only recover a session lock no other locker may hold (#15020)

Hyprland lets any client take over a held lock, so a second shell started
beside the desktop judged the real shell's live lock stranded, took it, and
then exited, leaving the session behind the failsafe while the real shell
still reported itself secure. Recovery now waits while any other Quickshell
or hyprlock runs, and gives up if one never exits.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

test/shell.d/hyprland-session-lock-stranded-test.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+fake_bin=$(mktemp -d)
+trap 'rm -rf "$fake_bin"' EXIT
+
+cat >"$fake_bin/omarchy-hyprland-session-locked" <<'SH'
+#!/bin/bash
+
+exit "$OMARCHY_TEST_LOCKED"
+SH
+
+# The lockers running are given, so the live desktop's own shell stays out of it.
+cat >"$fake_bin/pgrep" <<'SH'
+#!/bin/bash
+
+[[ $* == "-u $UID -x quickshell|qs|hyprlock" ]] || exit 3
+[[ -n $OMARCHY_TEST_LOCKERS ]] || exit 1
+printf '%s\n' $OMARCHY_TEST_LOCKERS
+SH
+chmod +x "$fake_bin"/*
+
+assert_status() {
+  local expected="$1" locked="$2" lockers="$3" description="$4" actual=0
+
+  PATH="$fake_bin:$PATH" OMARCHY_TEST_LOCKED="$locked" OMARCHY_TEST_LOCKERS="$lockers" \
+    "$ROOT/bin/omarchy-hyprland-session-lock-stranded" 100 || actual=$?
+
+  (( actual == expected )) || fail "$description" "expected exit $expected, got $actual"
+  pass "$description"
+}
+
+assert_status 0 0 "" "a lock with no locker alive is stranded"
+assert_status 0 0 "100" "the asking shell does not count as another locker"
+assert_status 1 1 "" "an unlocked session is not stranded"
+assert_status 2 2 "" "a compositor that cannot say leaves it undetermined"
+assert_status 2 0 "100 200" "a lock another locker may hold is left undetermined, so it is never taken"

test/shell.d/lock-stranded-recovery-test.sh

@@ -15,8 +15,8 @@ assert(
 )
 
 assert(
-  /id: strandedLockCheckProc[\s\S]*omarchy-hyprland-session-locked/.test(serviceQml),
-  'the startup check goes through the shared session lock helper'
+  /id: strandedLockCheckProc[\s\S]*omarchy-hyprland-session-lock-stranded \\"\$PPID\\"/.test(serviceQml),
+  'the startup check asks whether a lock has no live locker, skipping this shell'
 )
 
 // "No output to read" taken for "unlocked" leaves the failsafe up for good.