Promote SUB-OS out of alpha/beta to its first stable milestone. Bump
version.h to 1.0.0 with the "1.0.0-stable" banner string across every
arch target (codename Titan). Drop the ASCII wordmark from the README in
favour of the official circular SUB-OS logo image, and update the version
and release badges plus the Official Release link to v1.0.0.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Fh5z6V7nGPbHvqVG5p4CXX