Relicense from PolyForm Noncommercial to MIT OR Apache-2.0 (#158)

Relicenses Wickra from PolyForm Noncommercial 1.0.0 to the dual, OSI-approved **MIT OR Apache-2.0** (the de-facto Rust convention). Wickra becomes permissive, commercial-use-permitted open source; users may choose either license.

## Changes
- Replace `LICENSE` (PolyForm) with `LICENSE-MIT` + `LICENSE-APACHE` (full texts).
- Cargo: workspace `license = "MIT OR Apache-2.0"` (SPDX) + all 7 sub-crates switched from `license-file.workspace` to `license.workspace`.
- `deny.toml`: drop PolyForm from the allowlist.
- Python: `pyproject.toml` PEP 639 SPDX expression; remove the non-commercial classifier (verified: sdist metadata emits `License-Expression: MIT OR Apache-2.0`).
- Node: `package.json`, the 6 platform manifests and both lockfiles.
- README + Python/Node/WASM binding READMEs, CONTRIBUTING, CITATION.cff, PR template, and the WASM `pkg.license` step in `release.yml`.
- SECURITY.md: refresh supported versions 0.1.x -> 0.4.x.
- CHANGELOG: note the relicense under [Unreleased].

## Notes
- No code changes; metadata/text only. `cargo build` and `cargo deny check licenses` pass locally.
- GitHub will auto-detect "MIT, Apache-2.0" once this lands (currently NOASSERTION).
- Matching downstream changes (org `.github` profile, webpage, docs) are in separate PRs; merge those together with the relicense release so the live sites and org profile do not claim MIT before the packages do.

bindings/python/README.md

@@ -3,7 +3,7 @@
 [![CI](https://github.com/wickra-lib/wickra/actions/workflows/ci.yml/badge.svg)](https://github.com/wickra-lib/wickra/actions/workflows/ci.yml)
 [![codecov](https://codecov.io/gh/wickra-lib/wickra/branch/main/graph/badge.svg)](https://codecov.io/gh/wickra-lib/wickra)
 [![PyPI](https://img.shields.io/pypi/v/wickra.svg?logo=pypi&color=blue)](https://pypi.org/project/wickra/)
-[![License: PolyForm-NC](https://img.shields.io/badge/license-PolyForm--NC--1.0.0-purple)](https://github.com/wickra-lib/wickra/blob/main/LICENSE)
+[![License: MIT OR Apache-2.0](https://img.shields.io/badge/license-MIT_OR_Apache--2.0-blue)](https://github.com/wickra-lib/wickra#license)
 
 **Streaming-first technical indicators for Python. `pip install wickra` — no
 system dependencies, no C build tooling.**
@@ -66,7 +66,5 @@ risk. The library is provided **as is**, without warranty of any kind.
 
 ## License
 
-Licensed under the **PolyForm Noncommercial License 1.0.0**. Personal projects,
-research, education, non-profits, and hobby trading bots are all fine; the one
-thing not allowed is commercial sale of the software or of services built
-around it. See [LICENSE](https://github.com/wickra-lib/wickra/blob/main/LICENSE).
+Licensed under either of [Apache-2.0](https://github.com/wickra-lib/wickra/blob/main/LICENSE-APACHE)
+or [MIT](https://github.com/wickra-lib/wickra/blob/main/LICENSE-MIT) at your option.