fix: keep upstream entrypoint and update Linux runtime

[lookeey]

What changed

• Preserve the upstream Electron main entrypoint instead of forcing the removed .vite/build/bootstrap.js path.
• Exclude the macOS-only codex-code-mode-host payload from Linux resources.
• Update the bundled Codex CLI runtime pin from 0.140.0 to 0.144.1.

Why

The upstream 26.707 builds moved their entrypoint to .vite/build/early-bootstrap.js, and the previous Linux repack failed electron-builder's application entry check. The upstream archive also includes a macOS ARM code-mode host that must not be shipped as a Linux native payload.

Validation

• node --test test/build.test.mjs test/electron-builder-config.test.mjs
• Production canary build completed for 26.707.31428 build 5059.
• Beta canary build completed for 26.707.31428 build 5061.
• Bundled CLI reports codex-cli 0.144.1 on both installed Linux builds.