Bump the Electron desktop package version to 0.4.0, publish a macOS unsigned install helper, and let the release workflow continue when Developer ID signing is not configured.
Tested: bash -n desktop/scripts/install-macos-unsigned.sh
Tested: bun test scripts/pr/release-workflow.test.ts
Tested: bun run scripts/release.ts 0.4.0 --dry
Tested: git diff --check
Tested: bun run check:docs
Tested: bun run check:policy
Confidence: high
Scope-risk: moderate
9e4893ac36