[Protocol] Inline package assembly, fix cmake-format, add workflow_dispatch

- Replace the custom Node packaging script with a flat inline step
  (cp the .proto glob, cp the static files, npm version) so the
  workflow speaks the same shell idiom as the other workflows.
- Promote package.json and README.md to static files under
  libcockatrice_protocol/npm/ so contributors edit them in-place.
- Re-format libcockatrice_protocol/CMakeLists.txt per .cmake-format.json.
- Add workflow_dispatch (manual run; optional version input) and
  timeout-minutes: 10.
- Drop --provenance from npm publish: GitHub Packages doesn't
  attest Sigstore provenance.

libcockatrice_protocol/npm/README.md

@@ -0,0 +1,30 @@
+# @cockatrice/protocol
+
+Network protocol artifacts for [Cockatrice](https://github.com/Cockatrice/Cockatrice): the `.proto`
+definitions used by the desktop client, Servatrice, and the webclient, plus the
+authoritative protocol version constant they all share.
+
+## Install
+
+```sh
+npm install @cockatrice/protocol
+```
+
+The package is published to GitHub Packages under the `@cockatrice` scope; consumers
+need an `.npmrc` entry pointing the scope at `https://npm.pkg.github.com` and a
+`GITHUB_TOKEN` with `read:packages`.
+
+## Contents
+
+- `pb/*.proto` — every protobuf schema file from `libcockatrice_protocol`.
+- `protocol_version.json` — `{ "protocolVersion": <int> }`. Identical to the file
+  the C++ build reads via `configure_file()`.
+
+## Usage (TypeScript)
+
+```ts
+import protocolVersionInfo from "@cockatrice/protocol/protocol_version.json" with { type: "json" };
+export const PROTOCOL_VERSION = protocolVersionInfo.protocolVersion;
+```
+
+Point your protobuf code-generator (e.g. buf) at `node_modules/@cockatrice/protocol/pb`.