docs(platform-stack): transform to component cards with license and SEO descriptions

Replace long prose sections with oss-card shortcodes organized by platform role.
Each component now shows a logo, SPDX license, upstream source link, and a
300–500 character SEO-optimised description. Merges the content intent of the
licenses reference page into the platform stack guide.

Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: tym83 <6355522@gmail.com>

Author: 2 people