Fix auth cookie name (arm_token) + separate Run All from suite count

1. The driver set cookie name 'token' but the server uses 'arm_token',
   so Playwright always saw the login page instead of the surface.

2. Split "Run All (N suites)" into a "Run All" button + separate
   suite count label — count changes over time and shouldn't be
   part of the button text.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/test-runners/js/main.js

@@ -326,7 +326,7 @@
         <h2>Test Runners</h2>
         ${props.running
           ? html`<span class="ext-test-runners-running"><span class="ext-test-runners-spinner"></span> Running${props.runningSuite === 'all' ? ' all' : ''}...</span>`
-          : html`<button class="sw-btn sw-btn--primary" onClick=${props.onRunAll}>Run All (${props.suiteCount} suites)</button>`
+          : html`<button class="sw-btn sw-btn--primary" onClick=${props.onRunAll}>Run All</button> <span class="ext-test-runners-suite-count">${props.suiteCount} suites</span>`
         }
         ${s ? html`
           <div class="ext-test-runners-summary">