Condense Spectra development guidelines

Rewrite and simplify CLAUDE.md: update last-updated and reference CHANGELOG.md, replace a verbose tech and project-tree layout with a concise tech stack and compact directory overview, and condense the long CLI command examples into shorter usage summaries and global flags. Clean up MCP tools and reporting sections into compact lists, streamline code-style bullets, and remove large example blocks and noise to make the guidelines easier to read and maintain.

Author: angelovstanton