release: bump 0.4.6 -> 0.4.7 (#156)

Routine patch release. Ships the 10 pairwise stat-arb indicators added to Price Statistics in #154 (Rolling Correlation, Rolling Covariance, OU Half-Life, Kalman Hedge Ratio, Variance Ratio, Spread Bollinger Bands, Spread Hurst, Distance SSD, Granger Causality, Beta-Neutral Spread) together with the new Market Breadth family and its `CrossSection` input type (AdvanceDecline).

Version strings bumped `0.4.6 -> 0.4.7` across:
- `Cargo.toml` (workspace + `wickra-core` dep), `Cargo.lock`
- `bindings/python/pyproject.toml`
- `bindings/node/package.json` (+ 6 optional platform deps) and the 6 `npm/<platform>/package.json`
- `bindings/node/package-lock.json`, `examples/node/package-lock.json`
- `CHANGELOG.md` — `[Unreleased]` rolled into `[0.4.7] - 2026-06-03` with refreshed compare links

No code changes. `fmt` / `test --workspace` / `clippy --workspace -D warnings` green locally.

bindings/python/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "wickra"
-version = "0.4.6"
+version = "0.4.7"
 description = "Streaming-first technical indicators: incremental, fast, install-free."
 readme = "README.md"
 license = { text = "PolyForm-Noncommercial-1.0.0 with additional personal-account permissions; see LICENSE" }