Add Windows (PowerShell) support

- scripts/setup.ps1, scripts/pull-models.ps1, run.ps1 — PowerShell equivalents
  of the bash setup/pull/run scripts
- README + docs/DEPLOY.md: Windows quickstart and Task Scheduler autostart

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/DEPLOY.md

@@ -27,6 +27,27 @@ launchctl kickstart -k gui/$(id -u)/com.llm-router
 systemctl --user restart llm-router
 ```
 
+## Windows
+
+```powershell
+powershell -ExecutionPolicy Bypass -File .\scripts\setup.ps1        # venv + LiteLLM
+powershell -ExecutionPolicy Bypass -File .\scripts\pull-models.ps1  # pull models
+powershell -ExecutionPolicy Bypass -File .\run.ps1                  # LiteLLM + router
+```
+`run.ps1` starts LiteLLM in the background, waits for it, then runs the router in
+the foreground; closing it stops both.
+
+**Run at login (Task Scheduler):**
+```powershell
+$action  = New-ScheduledTaskAction -Execute "powershell.exe" `
+  -Argument "-ExecutionPolicy Bypass -WindowStyle Hidden -File `"$PWD\run.ps1`""
+$trigger = New-ScheduledTaskTrigger -AtLogOn
+Register-ScheduledTask -TaskName "llm-router" -Action $action -Trigger $trigger `
+  -Settings (New-ScheduledTaskSettingsSet -RestartCount 3 -RestartInterval (New-TimeSpan -Minutes 1))
+```
+Requires **Python 3.12** (`winget install Python.Python.3.12`) and Ollama for
+Windows. The router (stdlib Python) and LiteLLM run the same as on macOS/Linux.
+
 ## Networking
 
 - The router binds `ROUTER_HOST` (default `0.0.0.0` = reachable on the LAN).