release: bump 0.5.0 -> 0.5.1 (#162)
Version bump **0.5.0 → 0.5.1** for the Seasonality & Session family release (12 indicators, PR #161).
Bumped: `Cargo.toml` (workspace version + `wickra-core` dep), `Cargo.lock` (via `cargo build`), `bindings/python/pyproject.toml`, `bindings/node/package.json` (+ 6 `optionalDependencies`), the 6 `bindings/node/npm/<platform>/package.json`, both `package-lock.json` files, and `CHANGELOG.md` (`[Unreleased]` → `[0.5.1]` + compare URLs).
No code changes — version strings only.
