feat(host/windows,packaging): installer overhaul - branding, VB-CABLE, GameStream choice, driver uninstall

- Modern branded wizard: WizardStyle=modern dynamic windows11 (Inno >= 6.6,
  plain-modern fallback for older compilers; CI provisioning upgrades a
  pre-6.6 Inno). Brand-mark wizard side panels + header tiles (100-200% DPI)
  and a multi-size punktfunk.ico (SetupIconFile + Apps & Features), generated
  AND committed by branding/gen-branding.ps1 from the canonical brand geometry.
  Gotcha encoded in the script: ISCC rejects all-PNG icons, so entries <= 64px
  are classic DIBs (PNG only at 128/256), and the ICO is load-verified.

- VB-CABLE actually ships now: windows-host.yml never set VBCABLE_DIR, so every
  published installer silently omitted the virtual mic (broken mic passthrough
  in the field). CI provisions the pinned, SHA-256-verified official Pack45
  (provision-windows-punktfunk-extras.ps1) and the pack now FAILS on a
  supplied-but-invalid dir instead of shipping mic-less again. Attribution per
  VB-Audio's bundling grant surfaced in the visible wizard task text (vendor,
  vb-cable.com, donationware) on top of the licenses notice.

- GameStream (Moonlight) compat is a wizard task (checked by default) ->
  service install --gamestream=on|off writes PUNKTFUNK_HOST_CMD=
  serve[ --gamestream] into host.env. Only the two canonical values are ever
  rewritten - a hand-customized command line survives upgrades. Silent
  installs: /MERGETASKS="!gamestream".

- Driver uninstall (field report: our virtual-device drivers survived
  uninstall): new `driver uninstall [--gamepad]` removes the pf-vdisplay
  device node(s) + the pf-vdisplay/pf-dualsense/pf-xusb driver-store packages,
  wired into [UninstallRun] after service uninstall. Locale-safe by
  construction: devices matched on unlocalized VALUES (never pnputil's
  localized labels), packages found by INF content scan - validated against a
  German-locale box ("Instanz-ID:" parse; 7/7 punktfunk INFs matched, no
  foreign hits). VB-CABLE is deliberately left installed (shared third-party
  component with its own uninstaller).

Installer compile, cargo check/clippy/fmt, and the ASCII locale gate are green;
the wizard look + uninstall flow still need one on-glass pass on a disposable
box (this box runs the live host).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packaging/windows/pack-host-installer.ps1

@@ -132,6 +132,13 @@ $issLocal = Join-Path $OutDir 'punktfunk-host.iss'
 Copy-Item -LiteralPath $hostEnvSrc -Destination $hostEnv -Force
 Copy-Item -LiteralPath $readmeSrc -Destination $readme -Force
 Copy-Item -LiteralPath $iss -Destination $issLocal -Force
+# Branding (wizard BMPs + punktfunk.ico, committed outputs of branding/gen-branding.ps1): the .iss
+# references them as "branding\" relative to itself, so stage the dir next to the staged .iss.
+$brandStage = Join-Path $OutDir 'branding'
+if (Test-Path $brandStage) { Remove-Item $brandStage -Recurse -Force }
+New-Item -ItemType Directory -Force -Path $brandStage | Out-Null
+Copy-Item (Join-Path $here 'branding\*.bmp') $brandStage -Force
+Copy-Item (Join-Path $here 'branding\punktfunk.ico') $brandStage -Force
 
 # License/attribution payload bundled into {app}\licenses: the project's own MIT/Apache texts and the
 # generated third-party crate notices. The FFmpeg LGPL notice + license text are added to this same
@@ -198,7 +205,13 @@ if (-not $NoDriver) {
 # shipped intact); supply it via -VbCableDir / $env:VBCABLE_DIR pointing at the extracted official
 # package (must contain VBCABLE_Setup_x64.exe). Absent -> installer built WITHOUT the bundled cable; the
 # host then auto-installs the Steam Streaming pair as a fallback and mic passthrough needs a manual cable.
-if ($VbCableDir -and (Test-Path $VbCableDir) -and (Get-ChildItem -Path $VbCableDir -Filter 'VBCABLE_Setup*.exe' -ErrorAction SilentlyContinue)) {
+if ($VbCableDir -and -not ((Test-Path $VbCableDir) -and (Get-ChildItem -Path $VbCableDir -Filter 'VBCABLE_Setup*.exe' -ErrorAction SilentlyContinue))) {
+    # An explicitly-supplied dir that doesn't hold the package is a broken provisioning, not an
+    # opt-out - fail loudly instead of silently shipping an installer without the virtual mic
+    # (exactly the field regression this bundling fixes). Opt out by leaving VBCABLE_DIR unset.
+    throw "VbCableDir '$VbCableDir' has no VBCABLE_Setup*.exe - re-run scripts/ci/provision-windows-punktfunk-extras.ps1 (or unset VBCABLE_DIR to build without the virtual mic)"
+}
+if ($VbCableDir) {
     $vbStage = Join-Path $OutDir 'vbcable'
     if (Test-Path $vbStage) { Remove-Item -Recurse -Force $vbStage }
     New-Item -ItemType Directory -Force -Path $vbStage | Out-Null
@@ -211,7 +224,7 @@ if ($VbCableDir -and (Test-Path $VbCableDir) -and (Get-ChildItem -Path $VbCableD
     Copy-Item (Join-Path $here 'licenses\VB-CABLE-NOTICE.txt') -Destination $licStage -Force
     Write-Host "==> bundling VB-CABLE (virtual mic) from $VbCableDir -> $vbStage"
 }
-else { Write-Host "no -VbCableDir/`$env:VBCABLE_DIR (or no VBCABLE_Setup*.exe in it) -> installer built WITHOUT the bundled VB-CABLE virtual mic" }
+else { Write-Host "no -VbCableDir/`$env:VBCABLE_DIR -> installer built WITHOUT the bundled VB-CABLE virtual mic (CI always bundles it; see provision-windows-punktfunk-extras.ps1)" }
 
 # --- stage the FFmpeg shared DLLs (AMD/Intel AMF/QSV build) ------------------------------------
 # A host built with --features amf-qsv link-imports avcodec/avutil/swscale/... so the shared DLLs