add cross-platform setup scripts and frontend boilerplate for local AI image generation

scripts/setup-llama.ps1

@@ -0,0 +1,42 @@
+param([string]$Release = "b9631")
+
+$ErrorActionPreference = "Stop"
+$scriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
+$rootDir = Split-Path -Parent $scriptDir
+$appDir = Join-Path $rootDir "app"
+$toolsDir = Join-Path $appDir "tools"
+$llmRoot = Join-Path $appDir "llm-backend\win"
+
+function Install-LlamaArchive {
+    param([string]$Variant, [string]$AssetName)
+
+    $dest = Join-Path $llmRoot $Variant
+    $server = Join-Path $dest "llama-server.exe"
+    if (Test-Path $server) {
+        Write-Host "   OK  llama.cpp $Variant backend already ready."
+        return
+    }
+
+    $archive = Join-Path $toolsDir $AssetName
+    $extract = Join-Path $toolsDir "llama-$Variant-extract"
+    $url = "https://github.com/ggml-org/llama.cpp/releases/download/$Release/$AssetName"
+
+    New-Item -ItemType Directory -Force -Path $toolsDir, $dest | Out-Null
+    Remove-Item $archive, $extract -Recurse -Force -ErrorAction SilentlyContinue
+    Write-Host "   >>  Downloading llama.cpp $Variant backend ($Release)..."
+    Invoke-WebRequest -UseBasicParsing -Headers @{ "User-Agent" = "Local-AI-Studio" } -Uri $url -OutFile $archive
+    Expand-Archive -Path $archive -DestinationPath $extract -Force
+
+    Get-ChildItem $extract -Recurse -File | ForEach-Object {
+        Copy-Item $_.FullName (Join-Path $dest $_.Name) -Force
+    }
+    Remove-Item $archive, $extract -Recurse -Force -ErrorAction SilentlyContinue
+
+    if (-not (Test-Path $server)) {
+        throw "llama-server.exe was not found after extracting $AssetName"
+    }
+    Write-Host "   OK  llama.cpp $Variant backend installed."
+}
+
+Install-LlamaArchive -Variant "vulkan" -AssetName "llama-$Release-bin-win-vulkan-x64.zip"
+Install-LlamaArchive -Variant "cpu" -AssetName "llama-$Release-bin-win-cpu-x64.zip"