v0.3.4.1 — relauncher hardening

Small follow-up to v0.3.4. An independent code review turned up one concrete, safe reduction: the updater's relaunch step was hiding its helper process two different ways at once (a PowerShell flag and a .NET process-creation flag), which is a specific pattern some antivirus ML heuristics weight on its own. One of those was redundant — the process was already fully hidden without it — so it's removed. No behavior change; the helper was never visible either way.

Everyone already on v0.3.4 will pick this up automatically the normal way. If you were still seeing a fresh Defender flag on every HDT launch after installing v0.3.4, this release is worth grabbing directly.