feat(todo): places are watched by a quiet service, and asked to notify (ADR 0033, D32)

The first walk showed two faults. Android gives a proximity alert of an
app in the background a fix every 30 minutes (17:04:38, then 17:34:43 on
the Pixel), so a short stop goes unseen. And the place did remind, at
17:36:43, but nothing had asked to notify, so Android showed nothing.

A foreground service of the type location now takes its own fixes while
places wait, under the quietest notification there is: as long as
reaching the nearest circle takes at 30 m/s, doubled while the phone
lies still, between 30 s and 5 min. A place with a reminder asks to
notify as any reminder does.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/todo/halkyon_todo_flutter/test/support/memory_location_gateway.dart

@@ -9,6 +9,9 @@ class MemoryLocationGateway() implements LocationReminderGateway {
   /// What the device allows.
   LocationAccess allowed = LocationAccess.always;
 
+  /// What the quiet notification of watching says.
+  String watchingSays = '';
+
   /// How often the places were handed over.
   int replaced = 0;
 
@@ -19,7 +22,10 @@ class MemoryLocationGateway() implements LocationReminderGateway {
   Future<void> replace(
     List<LocationWatch> watches, {
     required String channel,
+    String watching = '',
+    String watchingChannel = '',
   }) async {
+    watchingSays = watching;
     watched = watches;
     replaced++;
   }