ci: add local packaging reproduction entrypoint

[luoye520ww]

Problem

Native packaging failures were difficult to reproduce locally because each CI job used a different command and the required Node/npm/Electron/dependency state was not shown consistently.

Scope

This PR adds the ci:reproduce entry point for the three native package jobs. It does not change CI workflows or retry policy.

Usage

npm run ci:reproduce -- --job linux-package
npm run ci:reproduce -- --job windows-package
npm run ci:reproduce -- --job macos-package
npm run ci:reproduce -- --job linux-package --dry-run

Changes

• Accept only the three explicit package jobs.
• Print Node, npm, Electron, package-lock, and node_modules state before execution.
• Fail with a clear non-zero status when prerequisites are missing; never silently skip a step.
• Support Windows npm.cmd shims without interpolating user input into a shell command.
• Provide dry-run output for command review without executing packaging.

Safety

• Commands and arguments come from a fixed job table.
• Windows shell mode exists only for the fixed npm.cmd shim; no user-provided text is passed to the shell.
• No secrets, logs, or artifacts are uploaded or persisted.

Typecheck

npm.cmd run typecheck

Passed.

Tests

node --test scripts/ci-reproduce.test.cjs
npm.cmd run lint
npm.cmd run build
git diff --check

Passed: 5 local reproduction tests; root typecheck, lint, and build passed; diff check passed.

Review performed

• Argument validation and command allow-list
• Windows .cmd compatibility
• Missing dependency behavior
• Dry-run vs real execution semantics
• Test quality and PR scope

Non-goals

• GitHub Actions workflow changes
• Automatic dependency installation
• Artifact upload or smoke execution beyond the selected package command

[luoye520ww]

This work is consolidated into #941, which contains the related CI diagnostics and packaged smoke fix as one tested PR. Closing this duplicate to avoid parallel review and PR noise.