Add CYD BLE foundation with NimBLE Nordic UART.

Reusable ble_core (+ optional LVGL ble_ui), flashable firmware/cyd, aligned with wifitest as a base feature.

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

firmware/export_from_build.ps1

@@ -0,0 +1,57 @@
+# Rebuild (optional) and refresh firmware/cyd from PlatformIO build output.
+# Usage:
+#   .\firmware\export_from_build.ps1
+#   .\firmware\export_from_build.ps1 -SkipBuild
+
+param([switch]$SkipBuild)
+
+$ErrorActionPreference = "Stop"
+$root = Split-Path -Parent (Split-Path -Parent $MyInvocation.MyCommand.Path)
+Set-Location $root
+
+$env:Path = "C:\Users\dsx2016\AppData\Local\Programs\Python\Python312\Scripts;" + $env:Path
+
+if (-not $SkipBuild) {
+  pio run -e cyd
+  if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+}
+
+$src = Join-Path $root ".pio\build\cyd"
+$dst = Join-Path $root "firmware\cyd"
+New-Item -ItemType Directory -Force -Path $dst | Out-Null
+
+foreach ($f in @("bootloader.bin", "partitions.bin", "firmware.bin")) {
+  $p = Join-Path $src $f
+  if (-not (Test-Path $p)) { Write-Error "Missing build artifact: $p" }
+  Copy-Item $p $dst -Force
+}
+
+$bootApp = Join-Path $env:USERPROFILE ".platformio\packages\framework-arduinoespressif32\tools\partitions\boot_app0.bin"
+if (-not (Test-Path $bootApp)) {
+  Write-Error "boot_app0.bin not found under PlatformIO packages"
+}
+Copy-Item $bootApp (Join-Path $dst "boot_app0.bin") -Force
+
+$git = ""
+try { $git = (git -C $root rev-parse --short HEAD).Trim() } catch { $git = "unknown" }
+$date = Get-Date -Format "yyyy-MM-dd"
+$hashes = Get-ChildItem (Join-Path $dst "*.bin") | Get-FileHash -Algorithm SHA256
+$lines = @(
+  "name: CYD BLE (cyd)",
+  "git: $git",
+  "date: $date",
+  "board: ESP32-2432S028R (ILI9341)",
+  "features: NimBLE Nordic UART, LVGL status UI, SoftSPI touch",
+  "flash_size: 4MB",
+  "offsets:",
+  "  0x1000  bootloader.bin",
+  "  0x8000  partitions.bin",
+  "  0xe000  boot_app0.bin",
+  "  0x10000 firmware.bin",
+  "sha256:"
+)
+foreach ($h in $hashes) {
+  $lines += ("  {0,-15} {1}" -f (Split-Path $h.Path -Leaf), $h.Hash)
+}
+$lines | Set-Content -Encoding utf8 (Join-Path $dst "VERSION.txt")
+Write-Host "Exported -> $dst (git $git)"