fix(browser): discover CDP websocket from bare ws:// URL before attach (#68715)

* fix(browser): discover CDP websocket from bare ws:// URL before attach

When browser.cdpUrl is set to a bare ws://host:port (no /devtools/ path), ensureBrowserAvailable would call isChromeReachable -> canOpenWebSocket against the URL verbatim. Chrome only accepts WebSocket upgrades at the specific path returned by /json/version, so the handshake failed immediately with HTTP 400. With attachOnly: true, that surfaced as:

  Browser attachOnly is enabled and profile "openclaw" is not running.

even though the CDP endpoint was reachable and the profile was healthy. Reproduced by the new tests in chrome.test.ts and cdp.test.ts (#68027).

Fix: introduce isDirectCdpWebSocketEndpoint(url) — true only when a ws/wss URL has a /devtools/<kind>/<id> handshake path. Route any other ws/wss cdpUrl (including the bare ws://host:port shape) through HTTP /json/version discovery by normalising the scheme via the existing normalizeCdpHttpBaseForJsonEndpoints helper. Apply this in isChromeReachable, getChromeWebSocketUrl, and createTargetViaCdp. Direct WS endpoints with a /devtools/ path are still opened without an extra discovery round-trip.

Fixes #68027

* test(browser): add seeded fuzz coverage for CDP URL helpers

Adds property-based / seeded-fuzz tests for the URL helpers the
attachOnly CDP fix depends on (#68027):

  - isWebSocketUrl
  - isDirectCdpWebSocketEndpoint
  - normalizeCdpHttpBaseForJsonEndpoints
  - parseBrowserHttpUrl
  - redactCdpUrl
  - appendCdpPath
  - getHeadersWithAuth

Follows the existing repo convention (see
src/gateway/http-common.fuzz.test.ts): no fast-check dep, small
mulberry32 PRNG + hand-rolled generators, deterministic per-describe
seeds so failures are reproducible.

Lifts cdp.helpers.ts coverage from 77.77% -> 89.54% statements,
67.9% -> 80.24% branches, 78% -> 90% lines. Remaining uncovered
lines are inside the WS sender internals (createCdpSender,
withCdpSocket, fetchCdpChecked rate-limit branch), which require
integration-style mocks and are unrelated to the attachOnly fix.

* test(browser): drive cdp.helpers/cdp/chrome to 100% coverage

Lifts the three files touched by the #68027 attachOnly fix to 100% statements/branches/functions/lines across the extensions test suite. Adds cdp.helpers.internal.test.ts, cdp.internal.test.ts, and chrome.internal.test.ts covering error paths, branch matrices, CDP session helpers, Chrome spawn/launch/stop flows, and canRunCdpHealthCommand. Defensively unreachable guards are annotated with c8 ignore + inline justifications.

* fix(browser): restore WS fallback for non-/devtools ws:// CDP URLs

When /json/version discovery is unavailable (or returns no
webSocketDebuggerUrl), fall back to treating the original bare ws/wss
URL as a direct WebSocket endpoint. This preserves the #68027 fix for
Chrome's debug port while restoring compatibility with Browserless/
Browserbase-style providers that expose a direct WebSocket root without
a /json/version endpoint.

Priority order for bare ws/wss cdpUrl inputs:
  1. /devtools/<kind>/<id> URL \u2192 direct handshake, no discovery (unchanged)
  2. bare ws/wss root \u2192 try HTTP discovery first; if discovery returns a
     webSocketDebuggerUrl use it; otherwise fall back to the original URL
     as a direct WS endpoint
  3. HTTP/HTTPS URL \u2192 HTTP discovery only, no fallback (unchanged)

Affected call sites: isChromeReachable, getChromeWebSocketUrl,
createTargetViaCdp.

Also renames a misleading test ('still enforces SSRF policy for direct
WebSocket URLs') to accurately describe what it tests: SSRF enforcement
on the navigation target URL, not on the CDP endpoint.

New tests added for all three fallback paths. Coverage remains 100% on
all three touched files (238 tests).

* fix: browser attachOnly bare ws CDP follow-ups (#68715) (thanks @visionik)

docs/tools/browser.md

@@ -316,15 +316,29 @@ Notes:
 ## Direct WebSocket CDP providers
 
 Some hosted browser services expose a **direct WebSocket** endpoint rather than
-the standard HTTP-based CDP discovery (`/json/version`). OpenClaw supports both:
+the standard HTTP-based CDP discovery (`/json/version`). OpenClaw accepts three
+CDP URL shapes and picks the right connection strategy automatically:
 
-- **HTTP(S) endpoints** — OpenClaw calls `/json/version` to discover the
-  WebSocket debugger URL, then connects.
-- **WebSocket endpoints** (`ws://` / `wss://`) — OpenClaw connects directly,
-  skipping `/json/version`. Use this for services like
-  [Browserless](https://browserless.io),
-  [Browserbase](https://www.browserbase.com), or any provider that hands you a
-  WebSocket URL.
+- **HTTP(S) discovery** — `http://host[:port]` or `https://host[:port]`.
+  OpenClaw calls `/json/version` to discover the WebSocket debugger URL, then
+  connects. No WebSocket fallback.
+- **Direct WebSocket endpoints** — `ws://host[:port]/devtools/<kind>/<id>` or
+  `wss://...` with a `/devtools/browser|page|worker|shared_worker|service_worker/<id>`
+  path. OpenClaw connects directly via a WebSocket handshake and skips
+  `/json/version` entirely.
+- **Bare WebSocket roots** — `ws://host[:port]` or `wss://host[:port]` with no
+  `/devtools/...` path (e.g. [Browserless](https://browserless.io),
+  [Browserbase](https://www.browserbase.com)). OpenClaw tries HTTP
+  `/json/version` discovery first (normalising the scheme to `http`/`https`);
+  if discovery returns a `webSocketDebuggerUrl` it is used, otherwise OpenClaw
+  falls back to a direct WebSocket handshake at the bare root. This covers
+  both Chrome-style remote debug ports and WebSocket-only providers.
+
+Plain `ws://host:port` / `wss://host:port` without a `/devtools/...` path
+pointed at a local Chrome instance is supported via the discovery-first
+fallback — Chrome only accepts WebSocket upgrades on the specific per-browser
+or per-target path returned by `/json/version`, so a bare-root handshake alone
+would fail.
 
 ### Browserbase