Refine research visibility, identity, and open report links

[qselmer]

Implements the approved website refinements without changing the site architecture:

• moves the Project-stage note to the end of Research;
• uses the single identity Quantitative Fisheries Scientist in the sidebar, Contact, and JSON-LD;
• adds verified official IMARPE open-access URLs to the two 2026 reports, with no invented DOI;
• marks every Research card with a public/private repository icon;
• private repository cards link to their internal project page and no longer send external visitors to a GitHub 404;
• public repository cards retain direct GitHub repository links;
• keeps generated Research/Publications/Profile fragments synchronized with the source changes.

No navigation or repository architecture changes are introduced.