Skip plain-forge install when Node.js is unavailable

The npx presence check passes when a version-manager shim (nvm, volta,
asdf) is on PATH without a working Node.js behind it. The npx call then
fails and aborts the whole installer: set -euo pipefail in bash,
ErrorActionPreference=Stop in PowerShell. The PowerShell installer also
marked plain-forge as installed even when the npx command failed.

Verify node actually runs before invoking npx, skip the step with a
clear message when it doesn't, and let a failed plain-forge install
print a retry hint instead of aborting the remaining setup steps. The
final next-steps screen already reminds the user to install plain-forge
manually whenever the step was skipped or failed.

Author: pedjaradenkovic

install/bash/install.sh

@@ -312,12 +312,20 @@ fi
 
 PLAIN_FORGE_INSTALLED=false
 if [[ ! "${INSTALL_PLAIN_FORGE:-}" =~ ^[Nn]$ ]]; then
-    if command -v npx &> /dev/null; then
-        npx plain-forge install < /dev/tty
-        PLAIN_FORGE_INSTALLED=true
+    # A stale nvm/volta/asdf shim can make npx resolvable without a working
+    # Node.js behind it, so verify node actually runs before invoking npx.
+    if command -v npx &> /dev/null && node --version &> /dev/null; then
+        # The install must not abort the rest of the setup if plain-forge
+        # fails (set -e is active), so run it inside the condition.
+        if npx plain-forge install < /dev/tty; then
+            PLAIN_FORGE_INSTALLED=true
+        else
+            echo -e "${GRAY}plain-forge installation failed. You can retry later with:${NC}"
+            echo -e "  npx plain-forge install"
+        fi
         echo ""
     else
-        echo -e "${GRAY}npx not found. Install Node.js, then run:${NC}"
+        echo -e "${GRAY}Node.js not found. Skipping plain-forge. Install Node.js, then run:${NC}"
         echo -e "  npx plain-forge install"
         echo ""
     fi

install/powershell/install.ps1

@@ -347,12 +347,35 @@ if ($nonInteractive) {
 
 $plainForgeInstalled = $false
 if ($installPlainForge -notmatch '^[Nn]$') {
-    if (Get-Command npx -ErrorAction SilentlyContinue) {
-        npx plain-forge install
-        $plainForgeInstalled = $true
+    # A stale version-manager shim can make npx resolvable without a working
+    # Node.js behind it, so verify node actually runs before invoking npx.
+    $nodeWorks = $false
+    if ((Get-Command node -ErrorAction SilentlyContinue) -and (Get-Command npx -ErrorAction SilentlyContinue)) {
+        try {
+            & node --version *> $null
+            $nodeWorks = ($LASTEXITCODE -eq 0)
+        } catch {
+            $nodeWorks = $false
+        }
+    }
+    if ($nodeWorks) {
+        # A plain-forge failure must not abort the rest of the setup
+        # ($ErrorActionPreference is 'Stop').
+        try {
+            npx plain-forge install
+            if ($LASTEXITCODE -eq 0) {
+                $plainForgeInstalled = $true
+            }
+        } catch {
+            # fall through to the retry hint below
+        }
+        if (-not $plainForgeInstalled) {
+            Write-Host "${GRAY}plain-forge installation failed. You can retry later with:${NC}"
+            Write-Host "  npx plain-forge install"
+        }
         Write-Host ""
     } else {
-        Write-Host "${GRAY}npx not found. Install Node.js, then run:${NC}"
+        Write-Host "${GRAY}Node.js not found. Skipping plain-forge. Install Node.js, then run:${NC}"
         Write-Host "  npx plain-forge install"
         Write-Host ""
     }