chore(naming): rename package + code refs from openclaw-claude-proxy to OCP (#57)

The npm name `ocp` is squatted (deprecated `node-ocp` v0.0.1), so the
package name is renamed to `open-claude-proxy` (verified via
`npm view open-claude-proxy` → 404, confirming availability).

### Changes

- `package.json`:
  - `"name"`: `openclaw-claude-proxy` → `open-claude-proxy`
  - `"bin"` map UNCHANGED: both `openclaw-claude-proxy` and `ocp`
    binaries still resolve, preserving back-compat for existing installs
    that reference `openclaw-claude-proxy` as a CLI command.
- `setup.mjs`: header JSDoc + start.sh banner string
- `uninstall.mjs`: header JSDoc

### Intentionally NOT changed

- `server.mjs` startup banner (line 1628):
  `console.log('openclaw-claude-proxy v...')`. Editing `server.mjs`
  requires `cli.js:NNNN` citation per ALIGNMENT.md Rule 1, and a
  cosmetic log-string rename has no `cli.js` correspondence. Deferred
  — would need an ALIGNMENT.md scope justification PR if pursued.
- `bin/openclaw-claude-proxy` symlink/path: existing installs depend on
  this name; kept as a back-compat alias.

### Evidence

```
$ npm view ocp
ocp@0.0.1 | DEPRECATED — squatted by node-ocp
$ npm view open-claude-proxy
404 — available
```

Refs: audit (naming consistency).

Co-authored-by: dtzp555 <dtzp555@gmail.com>

package.json

@@ -1,5 +1,5 @@
 {
-  "name": "openclaw-claude-proxy",
+  "name": "open-claude-proxy",
   "version": "3.12.0",
   "description": "OCP (Open Claude Proxy) — use your Claude Pro/Max subscription as an OpenAI-compatible API for any IDE. Works with Cline, OpenCode, Aider, Continue.dev, OpenClaw, and more.",
   "type": "module",