diff --git a/offline-deps/checksums/SHA256SUMS.txt b/offline-deps/checksums/SHA256SUMS.txt
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+96159FCB523AE404B707186A75B4104EE23851E476A5E838E14584CF1E03F981  D:\Coding\AS_Test\offline-deps\installers\python-3.13.12-amd64.exe
+CA685AE40B7435706A978EB62A619D3F922C502A3340DE5B7CB14363275A8DE4  D:\Coding\AS_Test\offline-deps\wheels\jsbsim-1.3.0-cp313-cp313-win_amd64.whl
+5C70F1CC1C4EFBE316A572E2D8B9B9CC44E89B95F79CA3331553FBB63716E2BF  D:\Coding\AS_Test\offline-deps\wheels\numpy-2.4.4-cp313-cp313-win_amd64.whl
diff --git a/offline-deps/installers/python-3.13.12-amd64.exe b/offline-deps/installers/python-3.13.12-amd64.exe
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diff --git a/offline-deps/readme.md b/offline-deps/readme.md
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+# Offline JSBSim Environment Setup
+
+This folder contains the offline files needed to run the service JSBSim backend on a Windows x64 machine.
+
+## Included Files
+
+```text
+offline-deps/
+  installers/
+    python-3.13.12-amd64.exe
+  wheels/
+    jsbsim-1.3.0-cp313-cp313-win_amd64.whl
+    numpy-2.4.4-cp313-cp313-win_amd64.whl
+  checksums/
+    SHA256SUMS.txt
+  python-runtime/
+    ...
+
+venv/
+  Scripts/
+    python.exe
+```
+
+`python-runtime/` is a project-local Python installation used to create `venv/`.
+`venv/` is the runtime environment used by the Node service.
+
+## Fresh Offline Install
+
+Run these commands from the repository root:
+
+```powershell
+cd D:\Coding\AS_Test
+
+powershell.exe -ExecutionPolicy Bypass -File .\offline-deps\setup-jsbsim-offline.ps1
+```
+
+The script will:
+
+- install the bundled Python runtime into `offline-deps\python-runtime`
+- create `venv`
+- install JSBSim from `offline-deps\wheels`
+- write `service\.env.local`
+
+To force-create `venv` again:
+
+```powershell
+powershell.exe -ExecutionPolicy Bypass -File .\offline-deps\setup-jsbsim-offline.ps1 -Force
+```
+
+## Manual Install
+
+Run these commands from the repository root:
+
+```powershell
+cd D:\Coding\AS_Test
+
+offline-deps\installers\python-3.13.12-amd64.exe /quiet InstallAllUsers=0 TargetDir="%CD%\offline-deps\python-runtime" Include_launcher=0 PrependPath=0 Include_test=0 Include_doc=0 Include_tcltk=0 Include_pip=1
+
+offline-deps\python-runtime\python.exe -m venv venv
+
+.\venv\Scripts\python.exe -m pip install --no-index --find-links offline-deps\wheels jsbsim==1.3.0
+```
+
+## Verify Python Packages
+
+```powershell
+.\venv\Scripts\python.exe -c "import jsbsim, numpy; print('jsbsim', jsbsim.__version__); print('numpy', numpy.__version__)"
+```
+
+Expected versions:
+
+```text
+jsbsim 1.3.0
+numpy 2.4.4
+```
+
+## Run Service With JSBSim Backend
+
+If you used the one-click setup script, it already created `service\.env.local`.
+You can start the service directly:
+
+```powershell
+cd D:\Coding\AS_Test\service
+npm.cmd run start
+```
+
+Manual environment setup:
+
+```powershell
+cd D:\Coding\AS_Test\service
+
+$env:SIM_BACKEND='jsbsim'
+$env:JSBSIM_PYTHON='D:\Coding\AS_Test\venv\Scripts\python.exe'
+
+npm.cmd run start
+```
+
+The service URL remains:
+
+```text
+http://127.0.0.1:4317
+```
+
+## Smoke Test
+
+In a second PowerShell window:
+
+```powershell
+Invoke-RestMethod -Uri http://127.0.0.1:4317/health
+```
+
+Then test trim:
+
+```powershell
+$body = @{
+  aircraftId = 'c172p-jsbsim'
+  altitudeM = 1000
+  speedMps = 50
+  headingDeg = 0
+  flightPathAngleDeg = 0
+} | ConvertTo-Json -Depth 8
+
+Invoke-RestMethod -Uri http://127.0.0.1:4317/trim -Method Post -ContentType 'application/json' -Body $body
+```
+
+Then test straight simulation:
+
+```powershell
+$body = @{
+  aircraftId = 'c172p-jsbsim'
+  sampleRateHz = 5
+  durationSec = 1
+  initialState = @{
+    position = @(0, 1000, 0)
+    velocityMps = 50
+    headingDeg = 0
+  }
+  maneuver = @{
+    type = 'straight'
+    parameters = @{
+      flightPathAngleDeg = 0
+    }
+  }
+} | ConvertTo-Json -Depth 8
+
+Invoke-RestMethod -Uri http://127.0.0.1:4317/simulate -Method Post -ContentType 'application/json' -Body $body
+```
+
+## Notes
+
+- The current JSBSim backend supports `straight`, `climb`, and `descent` only.
+- `level-turn` is still handled by the mock backend until JSBSim control input scripting is added.
+- The current smoke-test aircraft is `c172p-jsbsim`.
+- If deploying to a different path, update `JSBSIM_PYTHON` to point at that machine's `venv\Scripts\python.exe`.
+- If using custom JSBSim aircraft data instead of the data bundled with the Python wheel, set `JSBSIM_ROOT`.
diff --git a/offline-deps/setup-jsbsim-offline.ps1 b/offline-deps/setup-jsbsim-offline.ps1
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+param(
+  [switch]$Force
+)
+
+$ErrorActionPreference = "Stop"
+
+$Root = Resolve-Path -LiteralPath (Join-Path $PSScriptRoot "..")
+$OfflineDeps = Join-Path $Root "offline-deps"
+$ServiceDir = Join-Path $Root "service"
+$Installer = Join-Path $OfflineDeps "installers\python-3.13.12-amd64.exe"
+$PythonRuntime = Join-Path $OfflineDeps "python-runtime"
+$RuntimePython = Join-Path $PythonRuntime "python.exe"
+$Venv = Join-Path $Root "venv"
+$VenvPython = Join-Path $Venv "Scripts\python.exe"
+$Wheels = Join-Path $OfflineDeps "wheels"
+$ServiceEnv = Join-Path $ServiceDir ".env.local"
+
+if (!(Test-Path -LiteralPath $ServiceDir)) {
+  throw "Could not find service directory. Run this script from the AS_Test project layout."
+}
+
+if (!(Test-Path -LiteralPath $Installer)) {
+  throw "Missing Python installer: $Installer"
+}
+
+if (!(Test-Path -LiteralPath $Wheels)) {
+  throw "Missing wheels directory: $Wheels"
+}
+
+if ($Force -and (Test-Path -LiteralPath $Venv)) {
+  Remove-Item -LiteralPath $Venv -Recurse -Force
+}
+
+if (!(Test-Path -LiteralPath $RuntimePython)) {
+  New-Item -ItemType Directory -Force -Path $PythonRuntime | Out-Null
+  $args = @(
+    "/quiet",
+    "InstallAllUsers=0",
+    "TargetDir=$PythonRuntime",
+    "Include_launcher=0",
+    "PrependPath=0",
+    "Include_test=0",
+    "Include_doc=0",
+    "Include_tcltk=0",
+    "Include_pip=1"
+  )
+
+  $process = Start-Process -FilePath $Installer -ArgumentList $args -Wait -PassThru -WindowStyle Hidden
+  if ($process.ExitCode -ne 0) {
+    throw "Python installer failed with exit code $($process.ExitCode)"
+  }
+}
+
+& $RuntimePython --version
+
+if (!(Test-Path -LiteralPath $VenvPython)) {
+  & $RuntimePython -m venv $Venv
+}
+
+& $VenvPython -m pip install --no-index --find-links $Wheels jsbsim==1.3.0
+& $VenvPython -c "import jsbsim, numpy; print('jsbsim', jsbsim.__version__); print('numpy', numpy.__version__)"
+
+@"
+SIM_BACKEND=jsbsim
+JSBSIM_PYTHON=$VenvPython
+"@ | Set-Content -LiteralPath $ServiceEnv -Encoding UTF8
+
+Write-Host ""
+Write-Host "JSBSim offline environment is ready."
+Write-Host "Service env written to: $ServiceEnv"
+Write-Host ""
+Write-Host "Start service with:"
+Write-Host "  cd $Root\service"
+Write-Host "  npm.cmd run start"
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