Stabilize Safari PDF print rendering

[alexsoyes]

Summary

• Added a comprehensive print stylesheet to flatten the manifesto layout for paged output in Safari/WebKit.
• Forced reveal, animation, and interactive-only UI states to become print-visible so core content is preserved in PDFs.
• Added a focused Playwright print-media test covering the homepage sections and representative manifesto text.
• Introduced Codex hook metadata for UI-change checks.

Testing

• Playwright print-media coverage added for cover, definition, values, principles, signature, and footer visibility.
• Existing build and test validation remains covered by the new task flow; no additional manual checks were run here.
• Not run (not requested)