Add agent-first Yield bootstrap

[bigboateng]

Summary

• add yskill bootstrap with repository, language, and coding-agent detection
• install and verify equivalent TypeScript, Python, Go, and Rust workflow builders
• add the @operatorstack/create-yield npm initializer and eight-package release verification
• make the README and language guides agent-first while retaining manual SDK guidance

Safety

• show all proposed repository changes before writing
• require confirmation unless --yes is explicit
• refuse symlink escapes, foreign adapters, and existing destinations
• use no install hooks for bootstrap writes

Verification

• go test ./...
• node --test packaging/*.test.mjs sdk/typescript/bin/*.test.mjs scripts/*.test.mjs skills/release-yield/src/*.test.mjs
• python3 -m unittest discover -s sdk/python -p "test_*.py"
• cargo test --manifest-path sdk/rust/Cargo.toml
• all four generated builder fixtures reach completed
• non-Git TypeScript bootstrap dry run leaves the repository unchanged
• workflow YAML parses and git diff --check passes