feat(orchestrator): radio icon in the header opens the radio spot on every tab

The header radio button opens the radio spot above the main area of the current tab. The Send button, the toolbar radio button and the Radio tab are gone, the mayday clears inside the spot without a Cancel mayday label, and the radio station probe waits for a visible row.

🎯 Fix: 92 %
💥 Break: 4 %
💸 Cost: 100 %
⏱️ Time: 100 %
🛡️ Security: 100 %
🏆 Score: 88
🚦 Gate: ✅ 90/5, cost and time <= 100, security 100 %

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_hub_surface.py

@@ -12,12 +12,12 @@ from kvb_orchestrator import council, events, settings, skill_scripts, view
 
 
 class TestHubSurface(HubCase):
-    def test_the_header_holds_only_the_title_the_palette_and_the_settings(self):
+    def test_the_header_holds_only_the_title_the_radio_the_palette_and_the_settings(self):
         html = self.index()
         self.assertIn("<title>Agent Orchestrator</title>", html)
         header = re.search(r'<header class="top">(.*?)</header>', html, re.DOTALL).group(1)
         self.assertIn("<h1>Agent Orchestrator</h1>", header)
-        self.assertEqual(re.findall(r'<button[^>]*id="([^"]+)"', header), ["palette-open", "settings-open"])
+        self.assertEqual(re.findall(r'<button[^>]*id="([^"]+)"', header), ["radio-open", "palette-open", "settings-open"])
         self.assertEqual(re.findall(r"<(?:nav|select|input|textarea)\b", header), [])
         for gone in ('id="rail"', 'id="inbox-bar"', 'id="status"', 'id="board-open"', 'id="rules-open"', 'id="timebar"'):
             with self.subTest(gone=gone):