Keep the colleague's microbu-esp32c5 tree in this repository

obu-firmware builds against vanetza-idf from microbu-esp32c5/external, but
that tree was gitignored, so a clone of this repository could not build the
firmware it ships. It is now committed here as ordinary files in its own
folder, microbu-esp32c5/: the colleague's commit cf4b99f plus the V2X2MAP
bridge's signature verification (--trust) used on the bench. Nothing is
fetched from or pushed to the colleague's repository; this repository and
its remotes carry everything. The folder's own .gitignore keeps build output,
downloaded components and private key material out, as it did there; the
committed file set is identical to that repository's tracked files.

The ESP32-C5 is still flashed from obu-firmware/, which only takes
vanetza-idf from microbu-esp32c5/, so the two stay separate folders.
FLASHING.md says how to take a newer version of the colleague's tree (copy
it over the folder, rebuild, test, commit).

microbu-esp32c5/tools/v2x2map-0.3.0/bridge/build_exe.ps1

@@ -0,0 +1,55 @@
+# Builds two Windows EXEs for V2X2MAP:
+#   dist\its-g5-bridge.exe  -- bridge only, starts directly (reads config\v2x2map.cfg)
+#   dist\its-g5-setup.exe   -- setup wizard + firmware flash
+#
+# Run from V2X2MAP\bridge:
+#   .\build_exe.ps1
+
+$ErrorActionPreference = 'Continue'
+
+# Refresh bundled firmware bins from the latest build/ if it exists.
+$buildDir = Resolve-Path "..\firmware\build" -ErrorAction SilentlyContinue
+if ($buildDir) {
+    Copy-Item "$buildDir\bootloader\bootloader.bin"             ".\firmware\bootloader.bin"       -Force
+    Copy-Item "$buildDir\partition_table\partition-table.bin"   ".\firmware\partition-table.bin"  -Force
+    Copy-Item "$buildDir\ota_data_initial.bin"                  ".\firmware\ota_data_initial.bin" -Force
+    Copy-Item "$buildDir\its-g5-receiver-firmware.bin"          ".\firmware\firmware.bin"         -Force
+    Write-Host "Firmware-Bins aktualisiert aus $buildDir"
+} else {
+    Write-Host "Kein ..\firmware\build\ gefunden -- bestehende firmware\*.bin werden verwendet."
+}
+
+# Ensure required packages are available.
+python -m pip install --quiet -r requirements.txt pyinstaller esptool pillow
+
+# Generate icons
+Write-Host ""
+Write-Host "=== Generiere Icons ==="
+python make_icons.py
+if ($LASTEXITCODE -ne 0) { Write-Warning "Icon-Generierung fehlgeschlagen -- baue ohne Icons weiter." }
+
+Write-Host ""
+Write-Host "=== Baue its-g5-bridge.exe (Bridge ohne Wizard) ==="
+python -m PyInstaller --noconfirm its-g5-bridge.spec
+if ($LASTEXITCODE -ne 0) { Write-Error "Bridge-Build fehlgeschlagen."; exit 1 }
+
+Write-Host ""
+Write-Host "=== Baue its-g5-setup.exe (Setup-Wizard und Flash) ==="
+python -m PyInstaller --noconfirm its-g5-setup.spec
+if ($LASTEXITCODE -ne 0) { Write-Error "Setup-Build fehlgeschlagen."; exit 1 }
+
+$bridge = (Get-Item "dist\its-g5-bridge.exe").Length / 1MB
+$setup  = (Get-Item "dist\its-g5-setup.exe").Length  / 1MB
+Write-Host ""
+Write-Host "Fertig:"
+Write-Host ("  dist\its-g5-bridge.exe  {0:N1} MB  -- Doppelklick zum Starten" -f $bridge)
+Write-Host ("  dist\its-g5-setup.exe   {0:N1} MB  -- Einrichten und Flashen" -f $setup)
+Write-Host ""
+Write-Host "Ordnerstruktur nach dem ersten Start:"
+Write-Host "  dist\"
+Write-Host "    its-g5-bridge.exe"
+Write-Host "    its-g5-setup.exe"
+Write-Host "    config\"
+Write-Host "      v2x2map.cfg      (von Setup geschrieben)"
+Write-Host "    recordings\"
+Write-Host "      its5_*.pcap      (PCAP-Aufnahmen)"