feat: add uninstaller scripts for all tools + restore yolo mode

Uninstallers (.sh + .ps1) for Claude, Gemini, Codex, Qwen:
- Remove npm package / binary
- Remove settings directory (~/.gemini, ~/.qwen, ~/.codex, ~/.claude)
- Remove env vars from bashrc/zshrc, /etc/environment, /etc/profile.d
- Remove npm registry config

Also: restore defaultApprovalMode=yolo (npm package now includes
Target 9a patch in settingsSchema.js)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

qwen/uqwen_uninstall.ps1

@@ -0,0 +1,46 @@
+# Qwen Code — Windows Uninstaller
+# Usage: powershell -ExecutionPolicy Bypass -File qwen\uqwen_uninstall.ps1
+
+$ErrorActionPreference = "Continue"
+
+Write-Host ""
+Write-Host "  +--------------------------------------+" -ForegroundColor Cyan
+Write-Host "  |   Qwen Code -- Windows Uninstaller   |" -ForegroundColor Cyan
+Write-Host "  +--------------------------------------+" -ForegroundColor Cyan
+Write-Host ""
+
+# ---- Uninstall npm package ----
+
+Write-Host "  Removing @qwen-code/qwen-code..." -ForegroundColor Cyan
+npm uninstall -g @qwen-code/qwen-code 2>$null
+Write-Host "  npm package removed" -ForegroundColor Green
+
+# ---- Remove settings ----
+
+$qwenDir = "$env:USERPROFILE\.qwen"
+if (Test-Path $qwenDir) {
+    Write-Host "  Removing $qwenDir..." -ForegroundColor Cyan
+    Remove-Item -Recurse -Force $qwenDir
+    Write-Host "  Settings removed" -ForegroundColor Green
+} else {
+    Write-Host "  No settings directory found" -ForegroundColor Yellow
+}
+
+# ---- Remove env vars ----
+
+Write-Host "  Removing environment variables..." -ForegroundColor Cyan
+[System.Environment]::SetEnvironmentVariable("QWEN_API_KEY", $null, "User")
+[System.Environment]::SetEnvironmentVariable("QWEN_BASE_URL", $null, "User")
+Remove-Item Env:QWEN_API_KEY -ErrorAction SilentlyContinue
+Remove-Item Env:QWEN_BASE_URL -ErrorAction SilentlyContinue
+Write-Host "  Env vars removed" -ForegroundColor Green
+
+# ---- Remove npm registry config ----
+
+Write-Host "  Removing npm registry config..." -ForegroundColor Cyan
+npm config delete "@qwen-code:registry" 2>$null
+Write-Host "  Registry config removed" -ForegroundColor Green
+
+Write-Host ""
+Write-Host "  Qwen Code fully uninstalled!" -ForegroundColor Green
+Write-Host ""