feat(browser): add chrome MCP existing-session support

src/browser/server-context.availability.ts

@@ -3,6 +3,11 @@ import {
   PROFILE_POST_RESTART_WS_TIMEOUT_MS,
   resolveCdpReachabilityTimeouts,
 } from "./cdp-timeouts.js";
+import {
+  closeChromeMcpSession,
+  ensureChromeMcpAvailable,
+  listChromeMcpTabs,
+} from "./chrome-mcp.js";
 import {
   isChromeCdpReady,
   isChromeReachable,
@@ -60,11 +65,19 @@ export function createProfileAvailability({
     });
 
   const isReachable = async (timeoutMs?: number) => {
+    if (profile.driver === "existing-session") {
+      await ensureChromeMcpAvailable(profile.name);
+      await listChromeMcpTabs(profile.name);
+      return true;
+    }
     const { httpTimeoutMs, wsTimeoutMs } = resolveTimeouts(timeoutMs);
     return await isChromeCdpReady(profile.cdpUrl, httpTimeoutMs, wsTimeoutMs);
   };
 
   const isHttpReachable = async (timeoutMs?: number) => {
+    if (profile.driver === "existing-session") {
+      return await isReachable(timeoutMs);
+    }
     const { httpTimeoutMs } = resolveTimeouts(timeoutMs);
     return await isChromeReachable(profile.cdpUrl, httpTimeoutMs);
   };
@@ -109,6 +122,9 @@ export function createProfileAvailability({
     if (previousProfile.driver === "extension") {
       await stopChromeExtensionRelayServer({ cdpUrl: previousProfile.cdpUrl }).catch(() => false);
     }
+    if (previousProfile.driver === "existing-session") {
+      await closeChromeMcpSession(previousProfile.name).catch(() => false);
+    }
     await closePlaywrightBrowserConnectionForProfile(previousProfile.cdpUrl);
     if (previousProfile.cdpUrl !== profile.cdpUrl) {
       await closePlaywrightBrowserConnectionForProfile(profile.cdpUrl);
@@ -138,6 +154,10 @@ export function createProfileAvailability({
 
   const ensureBrowserAvailable = async (): Promise<void> => {
     await reconcileProfileRuntime();
+    if (profile.driver === "existing-session") {
+      await ensureChromeMcpAvailable(profile.name);
+      return;
+    }
     const current = state();
     const remoteCdp = capabilities.isRemote;
     const attachOnly = profile.attachOnly;
@@ -238,6 +258,10 @@ export function createProfileAvailability({
 
   const stopRunningBrowser = async (): Promise<{ stopped: boolean }> => {
     await reconcileProfileRuntime();
+    if (profile.driver === "existing-session") {
+      const stopped = await closeChromeMcpSession(profile.name);
+      return { stopped };
+    }
     if (capabilities.requiresRelay) {
       const stopped = await stopChromeExtensionRelayServer({
         cdpUrl: profile.cdpUrl,