release: define Electron packaging and artifact layout

[ubugeeei]

Finding

There is no Electron packaging configuration or documented artifact layout. start-bin currently depends on Electron from node_modules plus dist/bin outputs in the working directory.

Evidence

• No electron-builder/forge packaging config is present.
• scripts/start-bin.mjs launches node_modules/.bin/electron against dist-electron/main.js.
• electron/main.ts searches process.cwd() and process.resourcesPath for binaries/assets.

Acceptance criteria

• Choose and document the packaging strategy.
• Define where backend/render binaries and dist-render assets live in packaged apps.
• Add a release build smoke path.

[ubugeeei]

対応済みです。修正は PR #1 / commit 9cf4498 に反映済みです。