Isometric renames verification fees to certification fees sitewide

Isometric rebranded its pricing page from 'verification fees' to 'certification fees' throughout — page title, section headings, table name, column headers, and body copy all updated. 'Credits' also replaced with 'certificates'.

Mission statement sentence removed from the Scaled pricing section. Previous copy stated 'Isometric's pricing reflects its mission to scale the carbon removal market responsibly and fast.' This sentence no longer appears in the after version.