docs: add MIT license and repository description (#4)

Repo had no license file and no description metadata. Adds MIT LICENSE,
a license badge and section in the README, and description/license/
repository fields in package.json.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Vinicius Rosa
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,5 +1,7 @@
 # Ymir
 
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
+
 6-DOF naval physics simulator — rigid-body hydrodynamics for ships and floating platforms under current, wind, waves, thrusters, rudders, and tug interactions.
 
 The engine is domain-agnostic by design. The naval module is the first application.
@@ -71,3 +73,7 @@ ctest --test-dir build
 
 - [docs/architecture/README.md](docs/architecture/README.md) — architecture wiki: bounded-context map, data-flow diagrams, ADR index
 - [AGENTS.md](AGENTS.md) — contributor rules, coding standards, include conventions, commit discipline
+
+## License
+
+MIT — see [LICENSE](LICENSE).

package.json

@@ -1,6 +1,13 @@
 {
   "name": "ymir",
+  "version": "0.1.0",
   "private": true,
+  "description": "6-DOF naval physics simulator — rigid-body hydrodynamics for ships and floating platforms under current, wind, waves, thrusters, rudders, and tug interactions.",
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/vinihcrosa/Ymir.git"
+  },
   "scripts": {
     "build": "turbo run build",
     "dev": "turbo run dev --parallel",