Fix correctness bugs across the helper scripts

panama-osd read the wrong brightnessctl field, showing the hardware
max instead of a percentage on any backlight device. panama-doctor
called three sibling scripts by bare name with nothing on PATH,
making three health checks permanently and falsely report broken; its
repair actions also reused the short probe timeout, so a slow-but-
successful restart was reported as failed. panama-wifi-qr left the
cleartext passphrase temp file behind on its failure path (the RETURN
trap doesn't fire on exit), and its nmcli parsing broke on connection
names containing a colon or backslash -- verified against a real
NetworkManager profile.

panama-power-profile's set command always returned success regardless
of whether the write actually took. panama-keyring's daemon-origin
check picked whichever gnome-keyring-daemon process happened to
enumerate first in /proc, defeating the exact dual-daemon scenario it
exists to detect; it now resolves the PID that actually owns the
Secret Service D-Bus name. gnf aborted before running a firmware
update whenever the metadata was already current (a non-error exit
under set -e), and its flatpak update lacked the -y its own docs
promise.

Claude-Session: https://claude.ai/code/session_01E6TJUAh41HaP25MVHWkhRZ

tests/quickshell/panama-doctor-contract.sh

@@ -109,6 +109,7 @@ run_doctor() {
     PANAMA_DOCTOR_STATE_HOME="$state_home" \
     PANAMA_DOCTOR_RUNTIME_DIR="$runtime_dir" \
     PANAMA_DOCTOR_PATH="$bin_dir" \
+    PANAMA_DOCTOR_SCRIPTS_DIR="$bin_dir" \
     PANAMA_DOCTOR_TIMEOUT="${PANAMA_DOCTOR_TIMEOUT:-0.2}" \
         /usr/bin/python3 "$doctor" "$@"
 }
@@ -375,6 +376,7 @@ run_repair() {
     PANAMA_DOCTOR_STATE_HOME="$state_home" \
     PANAMA_DOCTOR_RUNTIME_DIR="$runtime_dir" \
     PANAMA_DOCTOR_PATH="$bin_dir:/usr/bin" \
+    PANAMA_DOCTOR_SCRIPTS_DIR="$bin_dir" \
     PANAMA_DOCTOR_TIMEOUT=0.2 \
         /usr/bin/python3 "$doctor" "$@"
 }