Graphenium v0.5.0: Graph identity and relative paths

Graphenium v0.5.0

Added

• graph_info MCP tool exposing schema version, project root, build timestamp, extraction mode, languages, and counts
• Relative paths in all MCP tool outputs (get_node, get_neighbors, god_nodes, summarize_file, architecture_summary)
• Demo script uses relative directory discovery instead of hardcoded absolute paths

Fixed

• AST-only gm check output now clearly explains that resolution requires the semantic pass