Make the offered home address the one that gets used, and keep edits safe

An interrupted review pass pointed at four problems in the pill's dialog, each
confirmed against the Frame:

- The offer to add the Frame's LAN address appended it after the Tailscale name,
  which then kept winning on that network, so nothing changed. The offer now adds
  it first in the list (address-add takes first: true); away from home the
  Tailscale name still leads. A tested address that ranks above the one in use
  gets a Use now button that reconnects through it.
- A half-typed edit was thrown away when the connection state changed after
  focus left the input, and when the server refused the save. The edit row now
  stays until it is saved or cancelled.
- Pressing Enter twice sent the update twice.
- The offer's button could act on the previously selected headset.

Keyboard focus also stays on the same button of the same address when the rows
are rebuilt.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tests/test_devices.py

@@ -296,6 +296,20 @@ class Pins(Base):
 
 
 class Registry(Base):
+    def test_an_address_added_first_wins_on_its_own_network(self):
+        # The page's "Add 192.168.x.x" offer: the headset is reached over Tailscale, which has
+        # worked here before. The LAN address has to go ahead of it to be used at home.
+        d = self.reg.add_device("frame-4", hosts=["frame.tail1234.ts.net"])
+        self.reg.record_success(d["id"], "frame.tail1234.ts.net", "n-home", 6.0)
+        self.reg.add_address(d["id"], "192.168.1.40", kind="lan", first=True)
+        self.reg.record_success(d["id"], "192.168.1.40", "n-home", 1.0)  # Test now found it
+        addrs = self.reg.get(d["id"])["addresses"]
+        self.assertEqual([a["host"] for a in addrs], ["192.168.1.40", "frame.tail1234.ts.net"])
+        at_home = [a["host"] for a, _ in fd.order_addresses(addrs, "n-home", True)]
+        self.assertEqual(at_home[0], "192.168.1.40")
+        away = [a["host"] for a, _ in fd.order_addresses(addrs, "n-cafe", True)]
+        self.assertEqual(away[0], "frame.tail1234.ts.net")  # elsewhere Tailscale still leads
+
     def test_address_editing(self):
         d = self.reg.add_device("frame-3", hosts=["192.168.1.40"])
         a = self.reg.add_address(d["id"], "frame-3.local", label="mDNS")