docs: refine absolute terminology and correct Base34 references
Updated Hygrid (markdown)
docs: merge conceptual overview with technical implementation for Hygrid
docs: compact Hygrid page to focus on spatial substrate role
docs: formalize Hygrid coordinate system framing and WASM benefits
Consolidate wiki structure
Document Hygrid as a novel integer coordinate system
Refactor wiki: streamline architecture, merge benchmarks, and clean up sidebar
Reorganize wiki structure and create missing stubs