Resolve semantic memory leaks and stabilize IaC orchestration

[BLMgithub]

Context
Addresses memory accumulation in the semantic stage and infrastructure state-lock issues during CI. This stabilizes the pipeline for high-volume streaming and concurrent IaC deployments.

Implemented

• Performance: Resolve memory accumulation in the semantic stage to enable stable streaming.
• IaC: Implement concurrency controls to prevent Terraform state locks during parallel CI runs.
• Validation: Add memory stress tests and a scaling roadmap for cost efficiency.
• Code Quality: Prune unused logic and align stage docstrings with architectural refactoring.
• Documentation: Update pipeline diagrams and infrastructure guides to reflect current design-contract patterns.

Impact

• Reliability: Eliminates pipeline crashes caused by memory leaks during large-scale data streaming.
• Operational Stability: Prevents CI/CD failures and manual state recovery efforts via lock prevention.
• Maintainability: Standardized docstrings and updated stage diagrams reduce onboarding and debugging friction.