v0.2.0 — Visual Polish

First polish milestone for the HELIOS program meta-repo.

The Pages site at https://577industries.github.io/helios-program/ now features a custom hero with the 1,302-station-hours Gannon result (with climatological-v1 caveat preserved), 4 artifact status cards, a Mermaid dependency graph, and a custom sun-themed SVG logo. Palette refreshed from deep_purple/amber to blue/teal for better dark-mode contrast. Workflow refactored to use mkdocs-include-markdown-plugin directives instead of build-time cp aggregation, so source content stays canonical in companion/, plan/, orchestration/, specs/ — only footnotes.yaml is still copied (referenced as a relative download link).

No code changes in this tag; documentation + presentation only.