fix(input): force Genshin foreground via AttachThreadInput (auto-scan no longer aborts)

Auto-scan aborted immediately with "Genshin konnte nicht in den Vordergrund
geholt werden". Root cause: the focus call runs in the background input/capture
helper process, and Windows' foreground lock silently refuses SetForegroundWindow
from a process that is neither foreground nor the last input source. When the user
clicks "Auto-Scan starten" the Electron window is foreground, so the helper's plain
SetForegroundWindow is dropped and focus stays false.

Fix (both the C# sidecar and the PowerShell fallback): before SetForegroundWindow,
attach our thread's input queue to the target (and current-foreground) window
thread with AttachThreadInput and clear SPI_..FOREGROUNDLOCKTIMEOUT, then restore.
This is the same technique Inventory Kamera and other reliable automators use; it
is what our helper was missing after the old ALT-tap workaround was removed on the
wrong assumption that equal integrity level is sufficient (that only covers UIPI
input injection, not foreground changes).

Sidecar recompiled + republished; electron build green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

electron/preload.ts

@@ -14,6 +14,7 @@ contextBridge.exposeInMainWorld("assistantApi", {
   getAutomationGuard: () => ipcRenderer.invoke("automation:getGuard"),
   focusMainWindow: () => ipcRenderer.invoke("app:focusMainWindow"),
   focusGenshin: () => ipcRenderer.invoke("automation:focusGenshin"),
+  focusGenshinForScanStart: () => ipcRenderer.invoke("automation:focusGenshin"),
   getRuntimeInfo: () => ipcRenderer.invoke("app:getRuntimeInfo"),
   saveReviewSample: (sample: ReviewSamplePayload) => ipcRenderer.invoke("review:saveSample", sample),
   loadReviewSamples: (limit = 50) => ipcRenderer.invoke("review:loadSamples", limit),