test: harden dist-bundle regression guard + Node smoke test

Existing test only checked `globalThis.Bun` top-level destructures
and `__require` calls. Add two new test cases:

1. Raw Bun runtime API scanner: scans dist/index.js for any
   `Bun.<anyMethod>(` or `Bun.<anyMethod>.` call outside shim-safe
   patterns (runtime.Bun, globalThis.Bun, typeof Bun, and the
   "Bun is not defined" error-message string). Uses a negative
   lookbehind so shim indirection (`runtime.Bun.foo`) passes.

2. Node smoke test: imports dist/index.js under
   `node --input-type=module` and asserts stderr contains no
   `ReferenceError` and no `Bun is not defined`. The existing
   case 3 only checked exit code, which masked lazy-evaluation
   crashes that fire after import. Reading exports forces lazy
   module-level evaluation paths to run.

src/shared/dist-bundle-bun-globals.test.ts

@@ -1,9 +1,58 @@
+/// <reference types="bun-types" />
+
 import { existsSync } from "node:fs"
 import { describe, expect, test } from "bun:test"
 
 const DIST_INDEX = "dist/index.js"
 const GLOBAL_BUN_DESTRUCTURE = /^\s*(?:var|let|const)\s*\{[^}]*\}\s*=\s*globalThis\.Bun/gm
 const TOP_LEVEL_REQUIRE_CALL = "__require("
+const RAW_BUN_API_CALL = /(?<![.$\w])Bun\.[a-zA-Z_$][a-zA-Z_$0-9]*\s*[.(]/g
+const NODE_EXPORT_SMOKE_SCRIPT = [
+  "const mod = await import('./dist/index.js');",
+  "const keys = Object.keys(mod).join(',');",
+  "console.log('SMOKE_OK:' + keys);",
+].join("\n")
+
+function hasRawBunApiCall(line: string): boolean {
+  RAW_BUN_API_CALL.lastIndex = 0
+  return RAW_BUN_API_CALL.test(line)
+}
+
+function isInsideStringLiteral(line: string, position: number): boolean {
+  let quote: "'" | '"' | "`" | null = null
+  let escaped = false
+
+  for (let index = 0; index < position; index += 1) {
+    const char = line.charAt(index)
+
+    if (escaped) {
+      escaped = false
+      continue
+    }
+
+    if (quote !== null && char === "\\") {
+      escaped = true
+      continue
+    }
+
+    if (char === "'" || char === '"' || char === "`") {
+      if (quote === char) {
+        quote = null
+      } else if (quote === null) {
+        quote = char
+      }
+    }
+  }
+
+  return quote !== null
+}
+
+function formatOffendingLine(lineNumber: number, line: string): string {
+  const content = line.trim()
+  const truncated = content.length > 120 ? `${content.slice(0, 117)}...` : content
+
+  return `${lineNumber}: ${truncated}`
+}
 
 describe("dist bundle Bun globals", () => {
   test.skipIf(!existsSync(DIST_INDEX))("#given dist bundle #when scanned #then no globalThis.Bun destructures remain", async () => {
@@ -62,4 +111,66 @@ describe("dist bundle Bun globals", () => {
       stderr: "",
     })
   })
+
+  test.skipIf(!existsSync(DIST_INDEX))("#given dist bundle #when scanned for raw Bun runtime APIs #then no unshimmed Bun API calls remain", async () => {
+    expect(hasRawBunApiCall("Bun.file('dist/index.js')")).toBe(true)
+    expect(hasRawBunApiCall("runtime.Bun.file('dist/index.js')")).toBe(false)
+    expect(hasRawBunApiCall(".Bun.file('dist/index.js')")).toBe(false)
+    expect(hasRawBunApiCall("$Bun.file('dist/index.js')")).toBe(false)
+    expect(hasRawBunApiCall("Bun.spawnSync.options")).toBe(true)
+    expect(hasRawBunApiCall("Bun.readableStreamToText(stream)")).toBe(true)
+
+    const dist = await Bun.file(DIST_INDEX).text()
+    const offending: string[] = []
+    let insideJSDoc = false
+
+    for (const [index, line] of dist.split("\n").entries()) {
+      const trimmed = line.trimStart()
+
+      if (insideJSDoc || trimmed.startsWith("/**")) {
+        insideJSDoc = !trimmed.includes("*/")
+        continue
+      }
+
+      if (line.includes("runtime.Bun") || line.includes("globalThis.Bun") || line.includes("typeof Bun")) {
+        continue
+      }
+
+      RAW_BUN_API_CALL.lastIndex = 0
+      const rawMatch = [...line.matchAll(RAW_BUN_API_CALL)].find(
+        (match) => match.index !== undefined && !isInsideStringLiteral(line, match.index),
+      )
+
+      if (rawMatch) {
+        offending.push(formatOffendingLine(index + 1, line))
+      }
+    }
+
+    expect(
+      offending,
+      `Expected zero raw Bun API calls in dist/index.js but found ${offending.length}:\n${offending.join("\n")}`,
+    ).toEqual([])
+  })
+
+  test.skipIf(!existsSync(DIST_INDEX))("#given dist bundle #when imported and inspected under node --input-type=module #then stderr has no Bun reference errors", async () => {
+    const node = Bun.which("node")
+    if (!node) return
+
+    const proc = Bun.spawn({
+      cmd: [node, "--input-type=module", "-e", NODE_EXPORT_SMOKE_SCRIPT],
+      cwd: process.cwd(),
+      stdout: "pipe",
+      stderr: "pipe",
+    })
+
+    const stdout = await new Response(proc.stdout).text()
+    const stderr = await new Response(proc.stderr).text()
+    const exitCode = await proc.exited
+    const stderrLower = stderr.toLowerCase()
+
+    expect(exitCode, stderr.trim()).toBe(0)
+    expect(stdout).toContain("SMOKE_OK:")
+    expect(stderrLower).not.toContain("referenceerror")
+    expect(stderr).not.toContain("Bun is not defined")
+  })
 })