feat: passthrough fallback for vpr/vp i on low Node (#1909 #1916)

crates/vite_global_cli/src/cli.rs

@@ -901,6 +901,20 @@ pub async fn run_command_with_options(
         return Ok(std::process::ExitStatus::default());
     };
 
+    // Low-Node passthrough precheck: when the project's resolved Node is below
+    // the supported minimum AND the command is eligible (run / package manager),
+    // bypass the Vite+ JS CLI and run the project's own package manager directly.
+    // See docs/superpowers/specs/2026-06-23-low-node-passthrough-design.md
+    if commands::passthrough::is_eligible(&command) {
+        if let Some(node_version) = resolve_project_node_version(&cwd).await? {
+            if commands::passthrough::should_passthrough(&command, &node_version) {
+                let mut executor = crate::js_executor::JsExecutor::new(None);
+                let runtime = executor.ensure_project_runtime(&cwd).await?;
+                return commands::passthrough::execute(&cwd, &command, runtime).await;
+            }
+        }
+    }
+
     match command {
         // Category A: Package Manager Commands
         // Print the runtime header for `vp install` (when not silent).
@@ -1111,6 +1125,24 @@ pub fn try_parse_args_from_with_options(
     Args::from_arg_matches(&matches).map_err(|e| e.into())
 }
 
+/// Resolve the project's Node version string (if any), without forcing a
+/// download. Used by the passthrough precheck to decide activation.
+///
+/// Returns `None` when the project has no Node version source (no .node-version,
+/// no devEngines.runtime, no engines.node) — in that case the original path
+/// runs (which falls back to CLI/LTS runtime, above the minimum).
+async fn resolve_project_node_version(
+    cwd: &vite_path::AbsolutePath,
+) -> Result<Option<String>, Error> {
+    use vite_js_runtime::resolve_node_version;
+    // walk_up=true to match ensure_project_runtime's resolution
+    // (has_valid_version_source uses resolve_node_version(path, true) at
+    // js_executor.rs:189); using false here could disagree with the runtime
+    // version actually downloaded, causing passthrough to mis-fire.
+    let resolution = resolve_node_version(cwd, true).await?;
+    Ok(resolution.map(|r| r.version.to_string()))
+}
+
 #[cfg(test)]
 mod tests {
     use super::{

crates/vite_global_cli/src/commands/mod.rs

@@ -110,6 +110,9 @@ pub mod upgrade;
 // Category C: Local CLI Delegation
 pub mod delegate;
 
+// Low-Node passthrough (degrades eligible commands to the project's package manager)
+pub mod passthrough;
+
 #[cfg(test)]
 mod tests {
     use vite_path::AbsolutePathBuf;