Add DiffCompressor and fix hnswlib SIGILL crash on CI

feat(toin): add TOIN + CCR integration to IntelligentContextManager

Remove hardcoded source hint system from ContentRouter

Add comprehensive evaluation framework for compression accuracy

Add reasoning capability forwarding to HeadroomAgnoModel

Add dynamic anchor selection with content deduplication

Integrate DynamicContentDetector into CacheAligner (Phase 1)

Add quality retention eval and fix linting for Python 3.12

Add Phase 2 Progressive Summarization and fix Agno integration tests

Implement COMPRESS_FIRST strategy for IntelligentContextManager

Add IntelligentContextManager for semantic-aware context management

Add persistent memory system with zero-latency inline extraction

Add AST-based code compression and custom model configuration

Add LLMLingua-2 opt-in support to proxy server

Fix all ruff lint and format errors for CI

feat: Add CCR architecture, TOIN telemetry, and DevEx improvements

Initial commit: Headroom SDK - LLM context optimization toolkit