[REFACTOR] Installable desktop builds and local runtime packaging

[ksamaschke]

Scoped Behavior Slice

Improve structure, naming, and maintainability for 'Installable desktop builds and local runtime packaging' without changing externally verified behavior.

Test Command or Verification Path

• Re-run the scoped GREEN verification after cleanup.
• Run the relevant regression suite to confirm no behavior changed.

Required Evidence Format

• Link passing evidence back to the GREEN work-item.
• Capture passing regression or suite evidence after refactor cleanup.

Tracking

• Type: work-item
• Phase: refactor

Parent: #178

[ksamaschke]

REFACTOR evidence for installable desktop packaging

Regression command:
NODE_PATH="/Users/karsten/Work/Development/intelligentcode-ai/intelligent-code-agents/node_modules" node --test dist/tests/installer/desktop-release-packaging.test.js dist/tests/installer/desktop-preview-startup.test.js dist/tests/installer/bootstrap-launch.test.js

Result:

• passing regression coverage after packaging cleanup

Cleanup included:

• shared package-asset generation helper in build-desktop-manifests.mjs
• consistent release workflow, checksum, and documentation naming for final desktop artifacts

No externally verified behavior changed beyond the scoped packaging contract.

[ksamaschke]

Closed via merge of PR #196 into dev.