Add more configuration params

[vishesh92]

This pull request introduces a comprehensive set of configuration options for performance tuning and search quality in SeaGOAT. It adds new server-side configuration sections for vector search, text search, engine processing, and query defaults, allowing users to fine-tune behavior for different repository sizes and hardware constraints. The codebase is updated to use these new config values throughout, replacing previous hardcoded limits and improving flexibility.

Configuration System Enhancements

• Added new configuration sections (chroma, ripgrep, engine, query) to docs/configuration.md and seagoat/utils/config.py, with schema validation and sensible defaults for vector search, text search, engine processing, and query parameters. [1] [2] [3] [4]
• Updated documentation to include detailed descriptions of new settings and practical performance tuning examples for various scenarios (large repos, memory-constrained systems, faster analysis, better search quality).

Engine and Query Processing

• The engine now dynamically determines the minimum number of chunks to analyze and the number of worker threads based on configuration, replacing fixed values. [1] [2]
• Query endpoints in seagoat/server.py use configurable defaults for result limits and context lines, improving usability and consistency. [1] [2] [3]

Vector Search Improvements

• All ChromaDB vector search logic now uses configurable values for maximum vector distance, chunk fetch limits, and result over-fetching, replacing previous constants. [1] [2] [3]

Ripgrep Text Search Improvements

• Ripgrep caching and search logic now use configurable file size and memory-mapped cache limits, improving scalability and resource control. [1] [2] [3]
• Ripgrep search results are scored using the configured vector distance for consistency with vector search. [1] [2]

These changes make SeaGOAT much more configurable, allowing users to optimize performance and search quality for their specific use case.