Publish pipeline: goreleaser + Maven Central + npm (#1)

* feat(cli): add Version var and version subcommand

* build(gradle): introduce uatu.version property for lockstep releases

* build(sdk-android): swap GitHub Packages for vanniktech Maven Central plugin

* build(spec-api): make package publish-ready for npm

* ci(release): add goreleaser config for cross-platform uatu CLI builds

* ci: add ci and release GitHub Actions workflows

* ci: restrict ci.yml to PR + workflow_dispatch (no direct push to master)

* docs(release): add local release targets, env example, and install docs

* build(sdk-android): make signAllPublications conditional on signing key

* ci(release): stage sidecar JAR at embed path before go build

* chore(spec-api): regenerate package-lock for updated package.json

* ci: install protoc-gen-go plugins before buf generate

* ci: bump Node to 22 (required for --experimental-strip-types)

pkg/spec-api/README.md

@@ -0,0 +1,39 @@
+# @uatu/spec
+
+TypeScript spec API for [uatu](https://github.com/priyanshujain/uatu) — a property-based UI fuzzer for mobile apps.
+
+Spec authors write specs in TypeScript that describe what an app should *always* do (safety invariants), generate weighted actions to exercise the app, and extract structured state from the accessibility tree. The `uatu` CLI picks up the spec and drives the app under test.
+
+## Install
+
+```sh
+npm install --save-dev @uatu/spec
+```
+
+## Usage
+
+```ts
+import { extract, always, actions, Tap, weighted } from "@uatu/spec";
+
+export const spec = {
+  extract: extract((tree) => ({
+    onHomeScreen: tree.some((n) => n.text === "Home"),
+  })),
+
+  always: always(({ state }) => state.onHomeScreen || !state.startedOnHome),
+
+  actions: actions(({ tree }) =>
+    weighted([
+      [1, Tap(tree.first((n) => n.text === "Checkout"))],
+    ]),
+  ),
+};
+```
+
+## Version compatibility
+
+`@uatu/spec` is released in lockstep with the uatu CLI. Pin the same major/minor version as your installed `uatu` binary.
+
+## License
+
+Apache-2.0