[High Priority] Add build verification workflow for PRs

[Mossaka]

Context

From CI/CD Pipeline Gap Assessment (Discussion #227)

Description

Extract and enforce build checks on all PRs to catch build failures early before merge.

Acceptance Criteria

• Create dedicated build verification workflow or extract from existing workflows
• Run TypeScript compilation (npm run build) on all PRs
• Make workflow required for PR merges
• Ensure compatibility check across Node versions if applicable

Estimated Effort

Approximately 1 hour

Related

• Discussion CI/CD Pipeline and Integration Tests - Gap Assessment #227