Implement story 1.5: provisioning execution tile download cache validation wifi kill

Add tiles.py, airspace.py, wifi.join_home_wifi, portal /submit route, and rewire
provision.py main loop; all tasks and quality gates pass (56 tests, ruff clean).

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

tests/provisioning/test_portal.py

@@ -2,6 +2,7 @@ from unittest.mock import patch
 
 import pytest
 
+from planemapper.provisioning import ProvisioningError
 from planemapper.provisioning.portal import app
 
 
@@ -69,3 +70,54 @@ def test_find_location_error(client) -> None:
         resp = client.post("/find-location", data={"location": "ZZZZ", "radius": "100"})
     assert resp.status_code == 200
     assert "ICAO code not found" in resp.data.decode()
+
+
+def test_submit_success(client) -> None:
+    with (
+        patch("planemapper.provisioning.portal.wifi.join_home_wifi"),
+        patch("planemapper.provisioning.portal.tiles.download_and_composite"),
+        patch("planemapper.provisioning.portal.airspace.download"),
+        patch("planemapper.provisioning.portal.tiles.validate_cache"),
+        patch("planemapper.provisioning.portal.config.write"),
+        patch("planemapper.provisioning.portal.wifi.kill_wifi"),
+    ):
+        resp = client.post(
+            "/submit",
+            data={
+                "confirmed_lat": "51.5",
+                "confirmed_lon": "-0.1",
+                "confirmed_name": "London",
+                "radius": "100",
+                "wifi_ssid": "HomeNet",
+                "wifi_password": "secret",
+            },
+        )
+    assert resp.status_code == 200
+    assert b"Setup complete" in resp.data
+
+
+def test_submit_validation_failure(client) -> None:
+    with (
+        patch("planemapper.provisioning.portal.wifi.join_home_wifi"),
+        patch("planemapper.provisioning.portal.tiles.download_and_composite"),
+        patch("planemapper.provisioning.portal.airspace.download"),
+        patch(
+            "planemapper.provisioning.portal.tiles.validate_cache",
+            side_effect=ProvisioningError("bad png"),
+        ),
+        patch("planemapper.provisioning.portal.config.write"),
+        patch("planemapper.provisioning.portal.wifi.kill_wifi"),
+    ):
+        resp = client.post(
+            "/submit",
+            data={
+                "confirmed_lat": "51.5",
+                "confirmed_lon": "-0.1",
+                "confirmed_name": "London",
+                "radius": "100",
+                "wifi_ssid": "HomeNet",
+                "wifi_password": "secret",
+            },
+        )
+    assert resp.status_code == 200
+    assert b"Try again" in resp.data