docs: fix CDP endpoint authentication documentation

[yavzius]

Summary

The CDP documentation contains two inaccuracies:

1. Authentication method: States endpoints require CDP_SECRET header, but the implementation uses a query parameter
2. WebSocket path: Lists WS /cdp/devtools/browser/{id} but the actual endpoint is WS /cdp

Evidence

Actual implementation (src/routes/cdp.ts:155-157):

const url = new URL(c.req.url);
const providedSecret = url.searchParams.get('secret');  // query param, not header

Code comments confirm (src/routes/cdp.ts:11):

* Authentication: Pass secret as query param `?secret=<secret>` on WebSocket connect.

Bundled scripts use query params (skills/cloudflare-browser/scripts/cdp-client.js:25):

const wsUrl = `wss://${workerUrl}/cdp?secret=${encodeURIComponent(CDP_SECRET)}`;

Changes

• Updated endpoint table to show query parameter syntax
• Corrected WebSocket path from /cdp/devtools/browser/{id} to /cdp
• Changed "header" to "query parameter" in authentication note