fix: fall back to node when bun and tsx are not installed

cli/build/worker-pool.ts

@@ -1,5 +1,7 @@
 import fs from "node:fs"
 import path from "node:path"
+import { dirname } from "node:path"
+import { fileURLToPath } from "node:url"
 import type { PlatformConfig } from "@tscircuit/props"
 import type { PcbSnapshotSettings } from "lib/project-config/project-config-schema"
 import { ThreadWorkerPool } from "lib/shared/thread-worker-pool"
@@ -32,19 +34,27 @@ type BuildJob = {
     }
 }
 
+// import.meta.dir is Bun-only; import.meta.dirname is Node >=21.2
+// Cast to include both so TypeScript does not complain about either.
+type ImportMetaWithDir = { dir?: string; dirname?: string }
+const __metaDir: string =
+  (import.meta as unknown as ImportMetaWithDir).dir ??
+  (import.meta as unknown as ImportMetaWithDir).dirname ??
+  dirname(fileURLToPath(import.meta.url))
+
 const getWorkerEntrypointPath = (): string => {
   // Check for .ts file first (development), then .js (published/dist)
-  const tsPath = path.join(import.meta.dir, "build.worker.ts")
+  const tsPath = path.join(__metaDir, "build.worker.ts")
   if (fs.existsSync(tsPath)) {
     return tsPath
   }
   // When bundled, main.js is in dist/ and worker is in dist/build/
-  const jsBundledPath = path.join(import.meta.dir, "build", "build.worker.js")
+  const jsBundledPath = path.join(__metaDir, "build", "build.worker.js")
   if (fs.existsSync(jsBundledPath)) {
     return jsBundledPath
   }
   // Fallback: same directory
-  return path.join(import.meta.dir, "build.worker.js")
+  return path.join(__metaDir, "build.worker.js")
 }
 
 /**

cli/entrypoint.js

@@ -14,7 +14,11 @@ function commandExists(cmd) {
   }
 }
 
-const runner = commandExists("bun") ? "bun" : "tsx"
+const runner = commandExists("bun")
+  ? "bun"
+  : commandExists("tsx")
+    ? "tsx"
+    : process.execPath
 
 const __dirname = dirname(fileURLToPath(import.meta.url))
 const packageRoot = join(__dirname, "..")

cli/snapshot/worker-pool.ts

@@ -1,5 +1,7 @@
 import fs from "node:fs"
 import path from "node:path"
+import { dirname } from "node:path"
+import { fileURLToPath } from "node:url"
 import type { ProcessSnapshotFileOptions } from "lib/shared/process-snapshot-file"
 import { ThreadWorkerPool } from "lib/shared/thread-worker-pool"
 import type {
@@ -19,22 +21,26 @@ type SnapshotJob = {
   >
 }
 
+// import.meta.dir is Bun-only; import.meta.dirname is Node >=21.2
+// Cast to include both so TypeScript does not complain about either.
+type ImportMetaWithDir = { dir?: string; dirname?: string }
+const __metaDir: string =
+  (import.meta as unknown as ImportMetaWithDir).dir ??
+  (import.meta as unknown as ImportMetaWithDir).dirname ??
+  dirname(fileURLToPath(import.meta.url))
+
 const getWorkerEntrypointPath = (): string => {
-  const tsPath = path.join(import.meta.dir, "snapshot.worker.ts")
+  const tsPath = path.join(__metaDir, "snapshot.worker.ts")
   if (fs.existsSync(tsPath)) {
     return tsPath
   }
 
-  const jsBundledPath = path.join(
-    import.meta.dir,
-    "snapshot",
-    "snapshot.worker.js",
-  )
+  const jsBundledPath = path.join(__metaDir, "snapshot", "snapshot.worker.js")
   if (fs.existsSync(jsBundledPath)) {
     return jsBundledPath
   }
 
-  return path.join(import.meta.dir, "snapshot.worker.js")
+  return path.join(__metaDir, "snapshot.worker.js")
 }
 
 export const snapshotFilesWithWorkerPool = async (options: {