Bun adapter: plugin.name with characters outside [$a-zA-Z0-9_-] crashes onLoad #598

Environment

unplugin@3.0.0 + bun@1.3.13

Reproduction

// repro.ts — run with `bun repro.ts`
import { createBunPlugin } from 'unplugin'

await Bun.write('./entry.ts', "import x from 'virtual:foo'; console.log(x);\n")

const plugin = createBunPlugin(() => ({
  name: 'my:plugin', // ← colon
  resolveId(id) {
    return id === 'virtual:foo' ? id : null
  },
  load(id) {
    return id === 'virtual:foo' ? 'export default 1' : null
  },
}))()

await Bun.build({
  entrypoints: ['./entry.ts'],
  plugins: [plugin],
})

Describe the bug

When an unplugin plugin defines both resolveId and load, the Bun adapter treats it as a virtual-module provider and uses plugin.name directly as the namespace passed to build.onLoad. Bun's namespace validator only accepts characters in [$a-zA-Z0-9_-] (oven-sh/bun:src/js/builtins/BundlerPlugin.ts#L215-217).

Plugin names elsewhere in the unplugin/rollup/vite ecosystem commonly use : as a scope separator (e.g. tanstack-router:code-splitter:compile-virtual-file), so the raw name fails Bun's validator and crashes any plugin that virtualises modules.

Additional context

No response

Logs

201 | 				});
202 | 				for (const pluginName of virtualModulePlugins) build.onLoad({
                         ^
TypeError: namespace can only contain $a-zA-Z0-9_\-
      at validate (4:20)
      at onLoad (32:18)
      at setup (node_modules/unplugin/dist/index.mjs:202:58)
      at repro.ts:16:11