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_nav.py

@@ -21,8 +21,8 @@ console.log(JSON.stringify({
   tasks: N.viewsOf("tasks").map(([id, label]) => [id, label]),
   icon: N.ICONS.hierarchy,
   routes: hashes.map((hash) => N.route(hash)),
-  hashes: [["stream", null], ["inbox", null], ["rules", null], ["radio", null], ["agents", "chord"], ["artifacts", "3d"], ["tasks", "board"]].map(([screen, view]) => N.hashOf(screen, view)),
-  tabOf: ["stream", "inbox", "rules", "radio", "agents", "artifacts", "tasks"].map((screen) => N.tabOf(screen)),
+  hashes: [["stream", null], ["inbox", null], ["rules", null], ["agents", "chord"], ["artifacts", "3d"], ["tasks", "board"]].map(([screen, view]) => N.hashOf(screen, view)),
+  tabOf: ["stream", "inbox", "rules", "agents", "artifacts", "tasks"].map((screen) => N.tabOf(screen)),
 }));
 """
 
@@ -33,8 +33,8 @@ class TestNavModule(unittest.TestCase):
         done = subprocess.run(["node", "-e", NAV_PROBE, str(NAV)], capture_output=True, text=True, timeout=60, check=True)
         cls.data = json.loads(done.stdout)
 
-    def test_the_navigation_has_four_entries_and_stream_has_inbox_rules_and_radio(self):
-        stream = ["stream", "Stream", [["inbox", "Inbox"], ["rules", "Firewall"], ["radio", "Radio"]]]
+    def test_the_navigation_has_four_entries_and_stream_has_inbox_and_rules(self):
+        stream = ["stream", "Stream", [["inbox", "Inbox"], ["rules", "Firewall"]]]
         self.assertEqual(self.data["tabs"], [stream, ["agents", "Agents", []], ["artifacts", "Artifacts", []], ["tasks", "Tasks", []]])
 
     def test_agents_and_artifacts_offer_five_views_in_order_and_tasks_six(self):
@@ -71,7 +71,7 @@ class TestNavModule(unittest.TestCase):
             {"screen": "artifacts", "view": None, "redirect": None},
             {"screen": "agents", "view": "hierarchy", "redirect": "#agents/hierarchy"},
             {"screen": "artifacts", "view": "tree", "redirect": "#artifacts/tree"},
-            {"screen": "radio", "view": None, "redirect": None},
+            {"screen": "stream", "view": None, "redirect": "#stream", "spot": True},
             stream,
             {"screen": "tasks", "view": None, "redirect": None},
             {"screen": "tasks", "view": "board", "redirect": None},
@@ -86,8 +86,8 @@ class TestNavModule(unittest.TestCase):
         ])
 
     def test_every_screen_has_its_own_hash_and_tab(self):
-        self.assertEqual(self.data["hashes"], ["#stream", "#stream/inbox", "#stream/rules", "#stream/radio", "#agents/chord", "#artifacts/3d", "#tasks/board"])
-        self.assertEqual(self.data["tabOf"], ["stream", "stream", "stream", "stream", "agents", "artifacts", "tasks"])
+        self.assertEqual(self.data["hashes"], ["#stream", "#stream/inbox", "#stream/rules", "#agents/chord", "#artifacts/3d", "#tasks/board"])
+        self.assertEqual(self.data["tabOf"], ["stream", "stream", "stream", "agents", "artifacts", "tasks"])
 
 
 if __name__ == "__main__":