Prepare repo for going public: LICENSE, CONTRIBUTING, README status

CONTRIBUTING.md

@@ -0,0 +1,46 @@
+# Contributing
+
+ReactiveScript is an early-stage language design. The spec is the product;
+the reference implementation in `ref/` exists to check it.
+
+## How claims are made
+
+Every behaviour claim is either a numbered rule (`E-n`, `H-n`, `AC-n`, …;
+see the README's *Rule IDs*) or a scenario under `scenarios/`
+(program → actions → frames → verdict). A change to the language comes
+with the rule it adds or amends and at least one scenario that shows it.
+`scenarios/TEMPLATE.md` is the starting point for a new one.
+
+Decisions recorded in the spec as *ruled* with a date are settled; please
+open an issue rather than a PR to revisit one. Decisions marked *taken by
+default* are still open to change.
+
+Semantics follow Solid 2.0 (`solidjs/solid@next`, pinned in
+`ref/SOLID_NEXT`). An open question in Solid's
+`packages/signals/docs/RULES-FUNDAMENTALS.md` is open here too. Where this
+spec diverges from Solid, the divergence is recorded as a `DV-n` in
+`spec/05-holds.md` or `spec/10-server.md`.
+
+## Running the suite
+
+Solid is built from its `next` branch at the pinned commit (needs pnpm and a
+Rust toolchain):
+
+```sh
+sh ref/scripts/solid-next.sh   # checks out and builds ../solid-next
+cd ref && npm install
+npm test                       # interpreter over every scenario
+npm run oracle                 # the same scenarios lowered onto Solid
+npm run compiled               # compiled modules
+npm run ssr                    # streamed SSR + hydration in Chromium
+npm run types                  # TSX projection checked by TypeScript
+```
+
+`ref/README.md` describes each runner. Please run the suite before opening a
+pull request and note any scenario whose result changed.
+
+## Issues
+
+Bug reports and questions are welcome as GitHub issues. For a semantics
+question, a small `.rx` program and the frames you expected is the most
+useful form.

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Ryan Carniato
+
+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

@@ -5,6 +5,10 @@ semantics: equations by default, writes confined to imperative scope, ownership
 and async (pending, holds, lanes) as things the compiler checks rather than the
 runtime warns about.
 
+> **Status:** early design work. The spec, its scenarios and the reference
+> implementation change often, and nothing here is released. See
+> [CONTRIBUTING.md](CONTRIBUTING.md) to run the suite or propose a change.
+
 This repository is the **spec** and its **reference implementation**. The
 production compiler is a separate Rust crate over Solid's own
 `solidjs-compiler` (`spec/11-compiler.md`): ReactiveScript parses, checks
@@ -88,3 +92,7 @@ Scenario IDs: `S-<area>-n` for the areas above (`S-core`, `S-region`,
   - *Superset of `.tsx`, no SFCs* — superseded: expressions and JSX are
     TS's verbatim and a file is a module (07 §1); declarations are keywords
     (`source`, `x = e`), as 07 rules.
+
+## License
+
+[MIT](LICENSE)