chore(pm): vendor the Aramesh/PM platform under pm/ (squash of Aramesh/PM @ 91f3271)

The PM panel (PmPanelPage -> iframe /pm/) needs the project-management
platform served at /pm/ on the ERP domain. Source: org repo Aramesh/PM,
branch feature/project-management-platform. Update via:
git subtree pull --prefix=pm aramesh-pm feature/project-management-platform --squash

pm/start.ps1

@@ -0,0 +1,57 @@
+# Start the PM Construction Platform stack (postgres + api + frontend)
+# Run this from the PM folder:
+#
+#   powershell -ExecutionPolicy Bypass -File .\start.ps1
+
+$ErrorActionPreference = "Stop"
+$here = Split-Path -Parent $MyInvocation.MyCommand.Path
+Set-Location $here
+
+Write-Host ""
+Write-Host "==========================================================" -ForegroundColor Cyan
+Write-Host "  PM Construction Platform — Starting Docker Containers   " -ForegroundColor Cyan
+Write-Host "==========================================================" -ForegroundColor Cyan
+
+# 1. Verify Docker Engine is running
+try {
+    docker info > $null 2>&1
+    if ($LASTEXITCODE -ne 0) {
+        throw "Docker is not running"
+    }
+}
+catch {
+    Write-Host ""
+    Write-Host " [ERROR] Docker Desktop is not running or the Docker daemon is unreachable." -ForegroundColor Red
+    Write-Host " Please start Docker Desktop from the Start Menu, wait until it is running, and try again." -ForegroundColor Yellow
+    Write-Host ""
+    exit 1
+}
+
+# 2. Ensure erp_default network exists so compose never fails if ERP is not running
+$erpNet = docker network ls --filter name=^erp_default$ -q
+if (-not $erpNet) {
+    Write-Host "Creating bridge network 'erp_default' for optional ERP integration..." -ForegroundColor Gray
+    docker network create erp_default | Out-Null
+}
+
+# 3. Build & start containers
+Write-Host "Starting containers (build if necessary)..." -ForegroundColor Yellow
+docker compose up -d --build
+
+if ($LASTEXITCODE -ne 0) {
+    Write-Host "Build or startup failed. Run 'docker compose logs' to inspect." -ForegroundColor Red
+    exit 1
+}
+
+Write-Host ""
+Write-Host "Waiting for services to become healthy..." -ForegroundColor Yellow
+Start-Sleep -Seconds 5
+docker compose ps
+
+Write-Host ""
+Write-Host "PM Platform UI : http://localhost:8083" -ForegroundColor Green
+Write-Host "PM API Health  : http://localhost:8083/api/v1/health" -ForegroundColor Green
+Write-Host "Database       : localhost:5434 (db: pm, user: pm)" -ForegroundColor Green
+Write-Host "Default Admin  : admin / pm123456" -ForegroundColor Green
+Write-Host ""
+Write-Host "Stop: docker compose down   |   Full reset: docker compose down -v" -ForegroundColor DarkGray