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>

codex/ucodex_uninstall.ps1

@@ -0,0 +1,60 @@
+# Codex CLI — Windows Uninstaller
+# Usage: powershell -ExecutionPolicy Bypass -File codex\ucodex_uninstall.ps1
+
+$ErrorActionPreference = "Continue"
+
+Write-Host ""
+Write-Host "  +--------------------------------------+" -ForegroundColor Cyan
+Write-Host "  |   Codex CLI -- Windows Uninstaller   |" -ForegroundColor Cyan
+Write-Host "  +--------------------------------------+" -ForegroundColor Cyan
+Write-Host ""
+
+# ---- Remove binary ----
+
+$installDir = "$env:LOCALAPPDATA\Programs\codex"
+if (Test-Path "$installDir\codex.exe") {
+    Write-Host "  Stopping codex processes..." -ForegroundColor Cyan
+    Get-Process -Name "codex" -ErrorAction SilentlyContinue | Stop-Process -Force
+    Write-Host "  Removing $installDir..." -ForegroundColor Cyan
+    Remove-Item -Recurse -Force $installDir
+    Write-Host "  Binary removed" -ForegroundColor Green
+
+    # Remove from PATH
+    $userPath = [System.Environment]::GetEnvironmentVariable("Path", "User")
+    if ($userPath -like "*$installDir*") {
+        $newPath = ($userPath -split ";" | Where-Object { $_ -ne $installDir }) -join ";"
+        [System.Environment]::SetEnvironmentVariable("Path", $newPath, "User")
+        Write-Host "  Removed from PATH" -ForegroundColor Green
+    }
+} else {
+    Write-Host "  Codex binary not found at $installDir" -ForegroundColor Yellow
+    # Check other common locations
+    $altPath = (Get-Command codex -ErrorAction SilentlyContinue).Source
+    if ($altPath) {
+        Write-Host "  Found at: $altPath — remove manually" -ForegroundColor Yellow
+    }
+}
+
+# ---- Remove config ----
+
+$codexDir = "$env:USERPROFILE\.codex"
+if (Test-Path $codexDir) {
+    Write-Host "  Removing $codexDir..." -ForegroundColor Cyan
+    Remove-Item -Recurse -Force $codexDir
+    Write-Host "  Config removed" -ForegroundColor Green
+} else {
+    Write-Host "  No config directory found" -ForegroundColor Yellow
+}
+
+# ---- Remove env vars ----
+
+Write-Host "  Removing environment variables..." -ForegroundColor Cyan
+[System.Environment]::SetEnvironmentVariable("OPENAI_API_KEY", $null, "User")
+[System.Environment]::SetEnvironmentVariable("OPENAI_BASE_URL", $null, "User")
+Remove-Item Env:OPENAI_API_KEY -ErrorAction SilentlyContinue
+Remove-Item Env:OPENAI_BASE_URL -ErrorAction SilentlyContinue
+Write-Host "  Env vars removed" -ForegroundColor Green
+
+Write-Host ""
+Write-Host "  Codex CLI fully uninstalled!" -ForegroundColor Green
+Write-Host ""