openclaw-tps-mail cannot load under Node: @tpsdev-ai/cli/utils/mail statically imports utils/archive (bun:sqlite) #394

Summary

The openclaw-tps-mail plugin built from main (5f6a7cf, after #392) fails to load in the OpenClaw gateway:

[plugins] openclaw-tps-mail failed to load from .../plugins/openclaw-tps-mail/dist/src/index.js:
Error [ERR_UNSUPPORTED_ESM_URL_SCHEME]: Only URLs with a scheme in: file, data, and node are supported by the default ESM loader. Received protocol 'bun:'
[plugins] 1 plugin(s) failed to initialize (load: openclaw-tps-mail)

The gateway then comes up with only the other plugin registered and every agent inbox it was watching goes unprocessed until the previous build is restored.

Mechanism (verified)

• Since fix(mail): verify envelopes on promotion; make verification non-optional #377 the plugin imports promote, recoverPromoted and sweepStrandedPromoteScratch from @tpsdev-ai/cli/utils/mail.
• packages/cli/src/utils/mail.ts line 6 statically imports logEvent from ./archive.js.
• packages/cli/src/utils/archive.ts line 5 imports Database from bun:sqlite.
• The OpenClaw gateway runs under Node (v26 here), whose ESM loader rejects the bun: scheme at import time, so the whole plugin module graph fails before any code runs.
• The three functions the plugin uses never call the archiver; the coupling is purely the static import.
• The previous deployed build (2026-09-02, pre-fix(mail): verify envelopes on promotion; make verification non-optional #377) imports only @tpsdev-ai/agent and @tpsdev-ai/cli/utils/agent-keys and loads fine — that is why this was never seen before.

Why review and CI did not catch it

Every test and both reviews ran under bun test, where bun:sqlite resolves. The plugin is not part of the workspace CI (#393), and nothing loads dist/src/index.js under Node. The production runtime of this package is Node; the test runtime was bun.

Fix shape

1. Break the static chain: in utils/mail.ts, load the archiver lazily where it is actually used (dynamic import("./archive.js") inside the archiving path), or move logEvent behind a runtime adapter that uses node:sqlite when Bun is undefined (Node ≥ 22.13 ships it). The first is smaller and sufficient for the plugin.
2. Add a Node-load check to the plugin's tests and to CI: node --input-type=module -e "import('./dist/src/index.js')" from the plugin directory must succeed. This is the one assertion that reproduces the failure exactly.
3. Optionally, a workspace-level guard that any subpath the plugin imports from @tpsdev-ai/cli is free of bun: imports (a grep over the built dist reachable from those subpaths).

Refs #392, #377, #386, #393.