Update runtime checks and installer behavior

scripts/check-node-version.mjs

@@ -0,0 +1,35 @@
+const MIN_NODE_VERSION = "20.18.1";
+
+function parseNodeVersion(version) {
+	const [major = "0", minor = "0", patch = "0"] = version.replace(/^v/, "").split(".");
+	return {
+		major: Number.parseInt(major, 10) || 0,
+		minor: Number.parseInt(minor, 10) || 0,
+		patch: Number.parseInt(patch, 10) || 0,
+	};
+}
+
+function compareNodeVersions(left, right) {
+	if (left.major !== right.major) return left.major - right.major;
+	if (left.minor !== right.minor) return left.minor - right.minor;
+	return left.patch - right.patch;
+}
+
+function isSupportedNodeVersion(version = process.versions.node) {
+	return compareNodeVersions(parseNodeVersion(version), parseNodeVersion(MIN_NODE_VERSION)) >= 0;
+}
+
+function getUnsupportedNodeVersionLines(version = process.versions.node) {
+	return [
+		`feynman requires Node.js ${MIN_NODE_VERSION} or later (detected ${version}).`,
+		"Switch to Node 20 with `nvm install 20 && nvm use 20`, or use the standalone installer:",
+		"curl -fsSL https://feynman.is/install | bash",
+	];
+}
+
+if (!isSupportedNodeVersion()) {
+	for (const line of getUnsupportedNodeVersionLines()) {
+		console.error(line);
+	}
+	process.exit(1);
+}

scripts/install/install.ps1

@@ -146,6 +146,16 @@ Workarounds:
     Write-Host "$installBinDir is already on PATH."
   }
 
+  $resolvedCommand = Get-Command feynman -ErrorAction SilentlyContinue
+  if ($resolvedCommand -and $resolvedCommand.Source -ne $shimPath) {
+    Write-Warning "Current shell resolves feynman to $($resolvedCommand.Source)"
+    Write-Host "Run in a new shell, or run: `$env:Path = '$installBinDir;' + `$env:Path"
+    Write-Host "Then run: feynman"
+    if ($resolvedCommand.Source -like "*node_modules*@companion-ai*feynman*") {
+      Write-Host "If that path is an old global npm install, remove it with: npm uninstall -g @companion-ai/feynman"
+    }
+  }
+
   Write-Host "Feynman $resolvedVersion installed successfully."
 } finally {
   if (Test-Path $tmpDir) {

scripts/install/install.sh

@@ -160,6 +160,27 @@ require_command() {
   fi
 }
 
+warn_command_conflict() {
+  expected_path="$INSTALL_BIN_DIR/feynman"
+  resolved_path="$(command -v feynman 2>/dev/null || true)"
+
+  if [ -z "$resolved_path" ]; then
+    return
+  fi
+
+  if [ "$resolved_path" != "$expected_path" ]; then
+    step "Warning: current shell resolves feynman to $resolved_path"
+    step "Run now: export PATH=\"$INSTALL_BIN_DIR:\$PATH\" && hash -r && feynman"
+    step "Or launch directly: $expected_path"
+
+    case "$resolved_path" in
+      *"/node_modules/@companion-ai/feynman/"* | *"/node_modules/.bin/feynman")
+        step "If that path is an old global npm install, remove it with: npm uninstall -g @companion-ai/feynman"
+        ;;
+    esac
+  fi
+}
+
 resolve_release_metadata() {
   normalized_version="$(normalize_version "$VERSION")"
 
@@ -290,20 +311,22 @@ add_to_path
 case "$path_action" in
   added)
     step "PATH updated for future shells in $path_profile"
-    step "Run now: export PATH=\"$INSTALL_BIN_DIR:\$PATH\" && feynman"
+    step "Run now: export PATH=\"$INSTALL_BIN_DIR:\$PATH\" && hash -r && feynman"
     ;;
   configured)
     step "PATH is already configured for future shells in $path_profile"
-    step "Run now: export PATH=\"$INSTALL_BIN_DIR:\$PATH\" && feynman"
+    step "Run now: export PATH=\"$INSTALL_BIN_DIR:\$PATH\" && hash -r && feynman"
     ;;
   skipped)
     step "PATH update skipped"
-    step "Run now: export PATH=\"$INSTALL_BIN_DIR:\$PATH\" && feynman"
+    step "Run now: export PATH=\"$INSTALL_BIN_DIR:\$PATH\" && hash -r && feynman"
     ;;
   *)
     step "$INSTALL_BIN_DIR is already on PATH"
-    step "Run: feynman"
+    step "Run: hash -r && feynman"
     ;;
 esac
 
+warn_command_conflict
+
 printf 'Feynman %s installed successfully.\n' "$resolved_version"