Version bump 0.8.0 -> 0.9.0 (minor: URL-scheme handler feature + trust-boundary
hardening). pyproject/rpm/debian + README(en/ko) + CHANGELOG(en/ko) [0.9.0]
heading with ### Contributors (@notnotno, @twkirk161, @mdshahalam3,
@ajeshchrist, @numericOverflow, @GameSoul7Eugene).