[cleanup] Phase 4: CI/CD workflow consolidation

[AlexMikhalev]

Summary

Consolidate 30 CI workflows down to ~18.

Actions

• Remove redundant workflows (ci-optimized.yml, test-ci.yml)
• Consolidate release workflows (4 -> 2)
• Consolidate test workflows into single matrix
• Audit shell scripts for unused references
• Archive unreferenced scripts

Verification

• All PR checks pass on feature branch
• gh workflow list shows clean set

[AlexMikhalev]

PR #633 created. Removed 6 redundant workflows (30 -> 24).