docs: document runtime requirements for two-tier API

docs: clarify stackless as deliberate design choice, improve gitignore

fix(docs): remove old pre-Astro docs, fix home page sidebar, remove broken autodocs link

feat: major project restructure with async runtime, docs site, and full test suite

docs: rewrite CLAUDE.md to reflect current project state

docs(cookbook): add 5 new recipes and improve existing ones

feat(bench): add blocking pool benchmarks

feat(coroutine): add 7-architecture support and Chase-Lev work-stealing deque

fix(sync): fix use-after-free and memory visibility bugs in sync primitives

fix(test): make broadcast stress tests robust across optimization levels

fix(sync): fix use-after-free race in Mutex and RwLock unlock

fix(test): fix stress tests for sync primitives and add I/O stress tests

test(sync): add stress tests for remaining sync primitives

test(sync): add comprehensive stress tests for sync primitives

fix(sync): use mutex-protected access in Channel.isClosed()