Implement story 1.3: WiFi hotspot and captive portal form

Implement wifi.py (start_ap/stop_ap/kill_wifi with subprocess and ProvisioningError),
portal.py (Flask captive portal with Android/iOS/Windows probe redirects and 404 catch-all),
updated provision.py provisioning loop, and full test suite (38 passing).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/provisioning/test_portal.py

@@ -0,0 +1,47 @@
+import pytest
+
+from planemapper.provisioning.portal import app
+
+
+@pytest.fixture
+def client():
+    app.config["TESTING"] = True
+    with app.test_client() as c:
+        yield c
+
+
+def test_index_returns_200(client) -> None:
+    resp = client.get("/")
+    assert resp.status_code == 200
+
+
+def test_index_contains_form_fields(client) -> None:
+    resp = client.get("/")
+    data = resp.data.decode()
+    assert 'name="location"' in data
+    assert 'name="radius"' in data
+    assert 'name="wifi_ssid"' in data
+    assert 'name="wifi_password"' in data
+    assert "Find location" in data
+    assert "Set up device" in data
+
+
+def test_generate_204_redirects_to_index(client) -> None:
+    resp = client.get("/generate_204")
+    assert resp.status_code in (301, 302)
+    assert resp.headers["Location"].endswith("/")
+
+
+def test_hotspot_detect_redirects_to_index(client) -> None:
+    resp = client.get("/hotspot-detect.html")
+    assert resp.status_code in (301, 302)
+
+
+def test_ncsi_redirects_to_index(client) -> None:
+    resp = client.get("/ncsi.txt")
+    assert resp.status_code in (301, 302)
+
+
+def test_unknown_route_redirects_to_index(client) -> None:
+    resp = client.get("/some/random/path")
+    assert resp.status_code in (301, 302)

tests/provisioning/test_provision_loop.py

@@ -1,4 +1,8 @@
-from planemapper.provisioning import ProvisioningError
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from planemapper.provisioning import ProvisioningError, wifi
 
 
 def test_provisioning_error_is_exception() -> None:
@@ -10,3 +14,41 @@ def test_provisioning_error_can_be_raised_and_caught() -> None:
         raise ProvisioningError("test error")
     except ProvisioningError as e:
         assert str(e) == "test error"
+
+
+def test_start_ap_raises_on_hostapd_failure() -> None:
+    mock_fail = MagicMock()
+    mock_fail.returncode = 1
+    with patch("planemapper.provisioning.wifi._write_hostapd_conf"):
+        with patch("planemapper.provisioning.wifi.subprocess.run", return_value=mock_fail):
+            with pytest.raises(ProvisioningError, match="hostapd failed"):
+                wifi.start_ap()
+
+
+def test_start_ap_raises_on_dnsmasq_failure() -> None:
+    mock_ok = MagicMock()
+    mock_ok.returncode = 0
+    mock_fail = MagicMock()
+    mock_fail.returncode = 1
+    with patch("planemapper.provisioning.wifi._write_hostapd_conf"):
+        with patch(
+            "planemapper.provisioning.wifi.subprocess.run",
+            side_effect=[mock_ok, mock_fail],  # hostapd OK, dnsmasq fails
+        ):
+            with pytest.raises(ProvisioningError, match="dnsmasq failed"):
+                wifi.start_ap()
+
+
+def test_kill_wifi_raises_on_rfkill_failure() -> None:
+    mock_fail = MagicMock()
+    mock_fail.returncode = 1
+    with patch("planemapper.provisioning.wifi.subprocess.run", return_value=mock_fail):
+        with pytest.raises(ProvisioningError, match="rfkill failed"):
+            wifi.kill_wifi()
+
+
+def test_stop_ap_does_not_raise() -> None:
+    mock_ok = MagicMock()
+    mock_ok.returncode = 0
+    with patch("planemapper.provisioning.wifi.subprocess.run", return_value=mock_ok):
+        wifi.stop_ap()  # should not raise