Add PostgreSQL analytics dashboard prototype and realistic sample data

mockups/setup-database.ps1

@@ -0,0 +1,40 @@
+param([switch]$SkipDownload)
+$ErrorActionPreference = 'Stop'
+$repoRoot = Split-Path $PSScriptRoot -Parent
+Set-Location -LiteralPath $repoRoot
+$localRoot = Join-Path $repoRoot '.local'
+$pythonExe = Join-Path $repoRoot '.venv\Scripts\python.exe'
+New-Item -ItemType Directory -Force -Path $localRoot | Out-Null
+if (!(Test-Path -LiteralPath $pythonExe)) { py -3 -m venv .venv; if ($LASTEXITCODE) { throw 'Could not create Python environment.' } }
+& $pythonExe -m pip install -r mockups/requirements.txt
+if ($LASTEXITCODE) { throw 'Python dependency installation failed.' }
+
+if (!$env:DATABASE_URL) {
+    $postgresBin = Join-Path $localRoot 'pgsql\bin'
+    if (!(Test-Path -LiteralPath (Join-Path $postgresBin 'initdb.exe'))) {
+        $archive = Join-Path $localRoot 'postgresql.zip'
+        if (!(Test-Path -LiteralPath $archive)) {
+            if ($SkipDownload) { throw 'Local PostgreSQL binaries and archive are missing.' }
+            Write-Host 'Downloading PostgreSQL 18.6 portable binaries from EDB...'
+            Invoke-WebRequest 'https://get.enterprisedb.com/postgresql/postgresql-18.6-5-windows-x64-binaries.zip' -OutFile $archive
+        }
+        & $pythonExe -c "import zipfile; z=zipfile.ZipFile(r'.local/postgresql.zip'); [z.extract(n,r'.local') for n in z.namelist() if n.startswith(('pgsql/bin/','pgsql/lib/','pgsql/share/'))]"
+        if ($LASTEXITCODE) { throw 'Could not extract PostgreSQL binaries.' }
+    }
+    $configPath = Join-Path $localRoot 'database.json'
+    $dataPath = Join-Path $localRoot 'pgdata'
+    if (!(Test-Path -LiteralPath (Join-Path $dataPath 'PG_VERSION'))) {
+        $samplePassword = & $pythonExe -c "import secrets; print(secrets.token_hex(24))"
+        $passwordFile = Join-Path $localRoot 'init-password.txt'
+        [System.IO.File]::WriteAllText($passwordFile,$samplePassword,[System.Text.UTF8Encoding]::new($false))
+        & (Join-Path $postgresBin 'initdb.exe') -D $dataPath -U sample_owner --encoding=UTF8 --locale=C --auth-host=scram-sha-256 --auth-local=scram-sha-256 --pwfile=$passwordFile
+        if ($LASTEXITCODE) { throw 'PostgreSQL initialization failed.' }
+        Remove-Item -LiteralPath $passwordFile
+        $settings = @{ url = "postgresql://sample_owner:${samplePassword}@127.0.0.1:55432/stat_dashboard_sample" } | ConvertTo-Json
+        [System.IO.File]::WriteAllText($configPath,$settings,[System.Text.UTF8Encoding]::new($false))
+    }
+    & "$PSScriptRoot/start-postgres.ps1"
+}
+& $pythonExe mockups/manage_database.py init
+if ($LASTEXITCODE) { throw 'Database migration or sample seeding failed.' }
+Write-Host 'Ready. Run mockups/start-mockups.ps1 to open the database-backed mockups.'