Add the Supply run API, item toggles and the Push to Calendar hook

GET /api/v1/shopping/{weekStart} reads the week's Supply run with its
week label, counts and groups by plan day; POST
/api/v1/shopping/{weekStart}/generate makes or remakes it through
shopping.Generate; PATCH /api/v1/shopping/items/{id} sets an item's
needed flag and answers with the list's new counts, 409 archived once
the list is in the Supply archive and 404 for an unknown item.

A successful Push to Calendar now makes the pushed week's Supply run.
Generation runs after the push is recorded and never fails or undoes
it: the 200 answer reports supply_run generated, archived or failed,
and a failure is logged as an error.

Maestro task d076480c-6c59-4c57-9023-6941badb4520.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/server/google_test.go

@@ -69,7 +69,7 @@ func newGoogleEnv(t *testing.T) *googleEnv {
 	}
 	logger := slog.New(slog.NewJSONHandler(e.logs, &slog.HandlerOptions{Level: slog.LevelDebug}))
 	e.h, err = NewRouter(logger, "dev", nil, stubAuth{}, stubSessions{}, newTestSettings(t), newTestSearch(t), newTestAI(t),
-		newTestDinners(t), newTestSuggest(t), newTestPlan(t), svc, newTestRunner(t), newTestPhotos(t),
+		newTestDinners(t), newTestSuggest(t), newTestPlan(t), newTestShopping(t), svc, newTestRunner(t), newTestPhotos(t),
 		fstest.MapFS{"index.html": {Data: []byte(fixtureIndex)}})
 	if err != nil {
 		t.Fatal(err)