test: an organisation delete removes the blobs, Postgres tests skip under -short

TestOrganisationLogo asserted only that the system_files rows go; it now
also waits for the commit and asserts the logo's and avatar's originals and
thumbnails are gone from the bucket. The Postgres tests of the gap closure
call t.Skip under -short instead of returning, so -short runs report them
as skipped, not passed.

api_token_events_test.go

@@ -12,10 +12,10 @@ import (
 // TestAPITokenRevokeEvent pins plan 08's token-specific MCP revocation
 // (C-IN-02, user side): DELETE /tokens/{id} fires exactly one revoked
 // subject event for the user carrying that TokenID, so only the sessions of
-// that token end. Postgres only: under -short nothing runs.
+// that token end. Postgres only: skipped under -short.
 func TestAPITokenRevokeEvent(t *testing.T) {
 	if testing.Short() {
-		return
+		t.Skip("Postgres")
 	}
 	env := newAdminEnv(t)
 	spy := env.spySubjects()