Add Windows packaging with bundled UI and dual-mode PostgreSQL.

Ship installable releases via zip/Inno Setup with optional bundled Postgres, API-hosted SPA, manual update path, and CI workflow for future tag builds.

Co-authored-by: Cursor <cursoragent@cursor.com>

packaging/download_postgres.ps1

@@ -0,0 +1,57 @@
+param(
+    [string]$Version = "16.4-1",
+    [string]$OutDir = ""
+)
+
+$ErrorActionPreference = "Stop"
+. "$PSScriptRoot\_common.ps1"
+
+# EnterpriseDB binary zip (Windows x86-64). Override with -Version if the URL 404s.
+$ver = $Version
+$url = "https://get.enterprisedb.com/postgresql/postgresql-$ver-windows-x64-binaries.zip"
+
+$cache = if ($OutDir) { $OutDir } else { Join-Path $PSScriptRoot "cache" }
+$zipPath = Join-Path $cache "postgresql-$ver-windows-x64-binaries.zip"
+$extractRoot = Join-Path $cache "pgsql-$ver"
+$destPgsql = Join-Path $PSScriptRoot "postgres\pgsql"
+
+if (-not (Test-Path $cache)) {
+    New-Item -ItemType Directory -Path $cache -Force | Out-Null
+}
+
+Write-Host "==> PostgreSQL binaries URL: $url"
+if (-not (Test-Path $zipPath)) {
+    Write-Host "==> Downloading (large; may take several minutes)..."
+    Invoke-WebRequest -Uri $url -OutFile $zipPath -UseBasicParsing
+} else {
+    Write-Host "==> Using cached zip: $zipPath"
+}
+
+if (Test-Path $extractRoot) {
+    Remove-Item -Recurse -Force $extractRoot
+}
+New-Item -ItemType Directory -Path $extractRoot -Force | Out-Null
+Write-Host "==> Extracting..."
+Expand-Archive -Path $zipPath -DestinationPath $extractRoot -Force
+
+# Zip usually contains a top-level "pgsql" folder.
+$found = Get-ChildItem -Path $extractRoot -Recurse -Filter "pg_ctl.exe" -ErrorAction SilentlyContinue |
+    Select-Object -First 1
+if (-not $found) {
+    throw "pg_ctl.exe not found after extract; check zip layout"
+}
+$pgsqlSrc = Split-Path -Parent (Split-Path -Parent $found.FullName)
+Write-Host "==> Found pgsql tree: $pgsqlSrc"
+
+if (Test-Path $destPgsql) {
+    Remove-Item -Recurse -Force $destPgsql
+}
+New-Item -ItemType Directory -Path (Split-Path -Parent $destPgsql) -Force | Out-Null
+Copy-Item -Path $pgsqlSrc -Destination $destPgsql -Recurse -Force
+
+$pgCtl = Join-Path $destPgsql "bin\pg_ctl.exe"
+if (-not (Test-Path $pgCtl)) {
+    throw "install_failed: missing $pgCtl"
+}
+Write-Host "==> Bundled PostgreSQL ready: $destPgsql" -ForegroundColor Green
+Write-Host "    Tip: data directory is NOT here; setup_first_run / start scripts use the NetX data root."