chore(db): stop wiping databases with an older schema version

All installations are past schema version 2, so the one-time reset is gone;
data is never deleted on start (demo mode still resets). user_version is kept
for future migrations. Legal test uses an in-memory DB (cleanup race).

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

internal/storage/visibility_test.go

@@ -144,8 +144,9 @@ func TestVisibilityFollowsOrganizations(t *testing.T) {
 	}
 }
 
-func TestOutdatedSchemaIsWiped(t *testing.T) {
-	path := filepath.Join(t.TempDir(), "old.db")
+// Existing data must survive a restart, whatever user_version the database carries.
+func TestDataSurvivesRestart(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "keep.db")
 	store, err := NewStore(path)
 	if err != nil {
 		t.Fatalf("NewStore failed: %v", err)
@@ -159,8 +160,8 @@ func TestOutdatedSchemaIsWiped(t *testing.T) {
 		t.Fatalf("reopen failed: %v", err)
 	}
 	defer store.Close()
-	if n, _ := store.CountUsers(); n != 0 {
-		t.Fatalf("outdated database should start empty, found %d users", n)
+	if n, _ := store.CountUsers(); n != 1 {
+		t.Fatalf("data must be kept on restart, found %d users", n)
 	}
 	var v int
 	_ = store.db.QueryRow(`PRAGMA user_version`).Scan(&v)