Release 5.4.2

[Hydro74000]

Summary

• Bump ngPost version to 5.4.2
• Include VPN helper availability fixes from devel
• Ignore the global VPN_AUTO_CONNECT master switch when no usable VPN profile is selected/configured
• Warn in the GUI before posting without VPN when the helper is installed, the master switch is enabled, and no usable VPN profile is selected/configured; user can Continue or Cancel
• Keep per-server useVpn fail-closed and log actionable guidance when VPN setup is incomplete
• Make the OpenVPN helper detect the tunnel interface/IP from newer OpenVPN logs and kernel state, fixing could not determine tun interface
• Improve legacy config migration handling and user notifications at startup
• Include translated warning strings and regenerated Qt translation resources
• Include macOS CI runner pin to macos-15 for Qt 6.8.2 compatibility

Validation

• git diff --check
• bash -n src/vpn/scripts/ngpost-vpn-helper.sh
• OpenVPN parser smoke checks for netlink, peer, iproute, and ifconfig log shapes
• lrelease-qt6 for all src/lang/ngPost_*.ts files (existing duplicate Clear warnings only)
• App build in distrobox enter my-distrobox with qmake6 src/ngPost.pro CONFIG+=release && make -j$(nproc)
• tests/unit/tst_VpnProfile in distrobox enter my-distrobox (11 passed)

Notes

• Replaces PR Release 5.4.2 #11, which used release/5.4.2 as the head branch.
• Targeting master because this repository does not have an origin/main branch.
• Not merged; merge remains manual.
• After updating the app/AppImage, reinstall the VPN helper from the VPN dialog so /var/lib/ngpost/ngpost-vpn-helper.sh is replaced.