refactor: remove legacy spaces and migrate lists to standalone resources with direct sharing

internal/storage/sqlite.go

@@ -137,28 +137,6 @@ func (s *Store) migrate() error {
 	);
 	CREATE INDEX IF NOT EXISTS idx_task_lists_user ON task_lists(user_id, updated_at DESC);
 
-	CREATE TABLE IF NOT EXISTS spaces (
-		id TEXT PRIMARY KEY,
-		name TEXT NOT NULL,
-		icon TEXT NOT NULL DEFAULT '🏠',
-		description TEXT NOT NULL DEFAULT '',
-		invite_code TEXT UNIQUE NOT NULL,
-		is_personal INTEGER NOT NULL DEFAULT 0,
-		owner_id TEXT NOT NULL,
-		created_at TEXT NOT NULL,
-		FOREIGN KEY(owner_id) REFERENCES users(id) ON DELETE CASCADE
-	);
-
-	CREATE TABLE IF NOT EXISTS space_members (
-		space_id TEXT NOT NULL,
-		user_id TEXT NOT NULL,
-		role TEXT NOT NULL DEFAULT 'editor',
-		joined_at TEXT NOT NULL,
-		PRIMARY KEY (space_id, user_id),
-		FOREIGN KEY(space_id) REFERENCES spaces(id) ON DELETE CASCADE,
-		FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE
-	);
-
 	CREATE TABLE IF NOT EXISTS organizations (
 		id TEXT PRIMARY KEY,
 		name TEXT NOT NULL,
@@ -259,16 +237,32 @@ func (s *Store) migrate() error {
 
 	CREATE TABLE IF NOT EXISTS lists (
 		id TEXT PRIMARY KEY,
-		space_id TEXT NOT NULL,
+		user_id TEXT NOT NULL,
 		title TEXT NOT NULL,
 		icon TEXT NOT NULL DEFAULT '🛒',
 		list_type TEXT NOT NULL DEFAULT 'shopping',
 		updated_at TEXT NOT NULL,
 		created_at TEXT NOT NULL,
-		FOREIGN KEY(space_id) REFERENCES spaces(id) ON DELETE CASCADE
+		FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE
 	);
 
-	CREATE INDEX IF NOT EXISTS idx_lists_space ON lists(space_id, updated_at DESC);
+	CREATE INDEX IF NOT EXISTS idx_lists_user ON lists(user_id, updated_at DESC);
+
+	CREATE TABLE IF NOT EXISTS list_shares (
+		id TEXT PRIMARY KEY,
+		list_id TEXT NOT NULL,
+		target_type TEXT NOT NULL CHECK(target_type IN ('team', 'user')),
+		target_id TEXT NOT NULL,
+		role TEXT NOT NULL DEFAULT 'editor' CHECK(role IN ('editor', 'viewer')),
+		created_by TEXT NOT NULL,
+		created_at TEXT NOT NULL,
+		UNIQUE(list_id, target_type, target_id),
+		FOREIGN KEY(list_id) REFERENCES lists(id) ON DELETE CASCADE,
+		FOREIGN KEY(created_by) REFERENCES users(id) ON DELETE CASCADE
+	);
+
+	CREATE INDEX IF NOT EXISTS idx_list_shares_target ON list_shares(target_type, target_id);
+	CREATE INDEX IF NOT EXISTS idx_list_shares_list ON list_shares(list_id);
 
 	CREATE TABLE IF NOT EXISTS list_items (
 		id TEXT PRIMARY KEY,
@@ -342,14 +336,20 @@ func (s *Store) migrate() error {
 		"CREATE INDEX IF NOT EXISTS idx_doc_team_shares_team ON doc_team_shares(team_id);",
 		"CREATE INDEX IF NOT EXISTS idx_doc_team_shares_doc ON doc_team_shares(doc_id);",
 
-		"CREATE TABLE IF NOT EXISTS space_team_shares (id TEXT PRIMARY KEY, space_id TEXT NOT NULL, team_id TEXT NOT NULL, role TEXT NOT NULL DEFAULT 'editor', created_at TEXT NOT NULL, created_by TEXT NOT NULL, UNIQUE(space_id, team_id));",
-		"CREATE INDEX IF NOT EXISTS idx_space_team_shares_team ON space_team_shares(team_id);",
-		"CREATE INDEX IF NOT EXISTS idx_space_team_shares_space ON space_team_shares(space_id);",
+		"ALTER TABLE lists ADD COLUMN user_id TEXT NOT NULL DEFAULT '';",
+		"CREATE TABLE IF NOT EXISTS list_shares (id TEXT PRIMARY KEY, list_id TEXT NOT NULL, target_type TEXT NOT NULL CHECK(target_type IN ('team', 'user')), target_id TEXT NOT NULL, role TEXT NOT NULL DEFAULT 'editor' CHECK(role IN ('editor', 'viewer')), created_at TEXT NOT NULL, created_by TEXT NOT NULL, UNIQUE(list_id, target_type, target_id));",
+		"CREATE INDEX IF NOT EXISTS idx_list_shares_target ON list_shares(target_type, target_id);",
+		"CREATE INDEX IF NOT EXISTS idx_list_shares_list ON list_shares(list_id);",
 	}
 	for _, q := range columnMigrations {
 		_, _ = s.db.Exec(q)
 	}
 
+	// Clean up legacy space_id from documents and task_lists if empty or orphaned
+	_, _ = s.db.Exec(`DROP TABLE IF EXISTS spaces`)
+	_, _ = s.db.Exec(`DROP TABLE IF EXISTS space_members`)
+	_, _ = s.db.Exec(`DROP TABLE IF EXISTS space_team_shares`)
+
 	// Backfill username for existing accounts where username is empty
 	_, _ = s.db.Exec(`UPDATE users SET username = LOWER(SUBSTR(email, 1, INSTR(email, '@') - 1)) WHERE (username IS NULL OR username = '') AND INSTR(email, '@') > 0`)
 
@@ -442,13 +442,10 @@ func (s *Store) SeedStarterContent(user *domain.User) error {
 		_, _ = s.UpdateThoughtTriage(user.ID, keptTask.ID, "keep", "task", "", now[:10], "")
 	}
 
-	familySpace, err := s.CreateSpace(user.ID, "Familie & Zuhause", "🏡", "Geteilter Bereich für Einkäufe, Haushalt & Urlaubsplanung", false)
-	if err == nil && familySpace != nil {
-		shopList, err := s.CreateList(familySpace.ID, "Wocheneinkauf Supermarkt", "🛒", "shopping")
-		if err == nil && shopList != nil {
-			_, _ = s.CreateListItem(shopList.ID, "Hafermilch (Barista Edition)", "Kühlregal", "3x", 0)
-			_, _ = s.CreateListItem(shopList.ID, "Espressobohnen (100% Arabica)", "Kaffee & Tee", "1 kg", 1)
-		}
+	shopList, err := s.CreateList(user.ID, "Wocheneinkauf Supermarkt", "🛒", "shopping")
+	if err == nil && shopList != nil {
+		_, _ = s.CreateListItem(shopList.ID, "Hafermilch (Barista Edition)", "Kühlregal", "3x", 0)
+		_, _ = s.CreateListItem(shopList.ID, "Espressobohnen (100% Arabica)", "Kaffee & Tee", "1 kg", 1)
 	}
 
 	starterBlocks := []domain.DocumentBlock{
@@ -692,12 +689,8 @@ func (s *Store) GetDiscoverableUsers(viewerID string) ([]domain.User, error) {
 			SELECT tm2.user_id FROM team_members tm1
 			JOIN team_members tm2 ON tm1.team_id = tm2.team_id
 			WHERE tm1.user_id = ?
-			UNION
-			SELECT sm2.user_id FROM space_members sm1
-			JOIN space_members sm2 ON sm1.space_id = sm2.space_id
-			WHERE sm1.user_id = ?
 		)`,
-		viewerID, viewerID, viewerID,
+		viewerID, viewerID,
 	)
 	if err != nil {
 		return []domain.User{*viewer}, nil
@@ -879,15 +872,14 @@ func (s *Store) accessibleTaskListIDsQuery() string {
 		       SELECT task_list_id FROM task_list_shares 
 		       WHERE (target_type = 'user' AND target_id = ?) 
 		          OR (target_type = 'team' AND target_id IN (SELECT team_id FROM team_members WHERE user_id = ?))
-		   )
-		   OR (space_id != '' AND space_id IN (SELECT space_id FROM space_members WHERE user_id = ?))`
+		   )`
 }
 
 func (s *Store) GetThoughtByID(userID, thoughtID string) (*domain.Thought, error) {
 	row := s.db.QueryRow(
 		`SELECT id, user_id, content, tags, priority, source, status, is_completed, converted_type, converted_ref_id, due_date, task_list_id, kanban_status, notes, alarm_sent, created_at, triaged_at, subtasks
 		 FROM thoughts WHERE id = ? AND (user_id = ? OR task_list_id IN (`+s.accessibleTaskListIDsQuery()+`))`,
-		thoughtID, userID, userID, userID, userID, userID, userID,
+		thoughtID, userID, userID, userID, userID, userID,
 	)
 	return scanThought(row)
 }
@@ -940,7 +932,7 @@ func (s *Store) GetTasks(userID string, taskListID string) ([]domain.Thought, er
 			   AND task_list_id = ?
 			   AND (status = 'kept' OR (status = 'converted' AND converted_type = 'task'))
 			 ORDER BY is_completed ASC, CASE WHEN due_date = '' THEN 1 ELSE 0 END, due_date ASC, created_at DESC`,
-			userID, userID, userID, userID, userID, userID, taskListID,
+			userID, userID, userID, userID, userID, taskListID,
 		)
 	} else {
 		rows, err = s.db.Query(
@@ -949,7 +941,7 @@ func (s *Store) GetTasks(userID string, taskListID string) ([]domain.Thought, er
 			 WHERE (user_id = ? OR task_list_id IN (`+s.accessibleTaskListIDsQuery()+`))
 			   AND (status = 'kept' OR (status = 'converted' AND converted_type = 'task'))
 			 ORDER BY is_completed ASC, CASE WHEN due_date = '' THEN 1 ELSE 0 END, due_date ASC, created_at DESC`,
-			userID, userID, userID, userID, userID, userID,
+			userID, userID, userID, userID, userID,
 		)
 	}
 	if err != nil {
@@ -2190,339 +2182,9 @@ func (s *Store) GetCollaborators(currentUserID string) ([]domain.User, error) {
 	return users, nil
 }
 
-// --- SPACES & REALTIME LISTS ---
+// --- STANDALONE REALTIME LISTS & SHARING ---
 
-func (s *Store) CreateSpace(ownerID, name, icon, description string, isPersonal bool) (*domain.Space, error) {
-	if strings.TrimSpace(name) == "" {
-		return nil, errors.New("space name required")
-	}
-	if icon == "" {
-		icon = "🏠"
-	}
-	now := domain.NowISO()
-	inviteCode := strings.ToUpper(domain.NewID("inv")[4:12])
-	personalInt := 0
-	if isPersonal {
-		personalInt = 1
-	}
-
-	sp := &domain.Space{
-		ID:          domain.NewID("spc"),
-		Name:        strings.TrimSpace(name),
-		Icon:        icon,
-		Description: strings.TrimSpace(description),
-		InviteCode:  inviteCode,
-		IsPersonal:  isPersonal,
-		OwnerID:     ownerID,
-		CreatedAt:   now,
-	}
-
-	_, err := s.db.Exec(
-		`INSERT INTO spaces (id, name, icon, description, invite_code, is_personal, owner_id, created_at)
-		 VALUES (?, ?, ?, ?, ?, ?, ?, ?)`,
-		sp.ID, sp.Name, sp.Icon, sp.Description, sp.InviteCode, personalInt, sp.OwnerID, sp.CreatedAt,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	_, _ = s.db.Exec(
-		`INSERT INTO space_members (space_id, user_id, role, joined_at) VALUES (?, ?, 'owner', ?)`,
-		sp.ID, ownerID, now,
-	)
-	return s.GetSpaceByID(sp.ID)
-}
-
-func (s *Store) JoinSpaceByInviteCode(userID, inviteCode string) (*domain.Space, error) {
-	inviteCode = strings.ToUpper(strings.TrimSpace(inviteCode))
-	var spaceID string
-	err := s.db.QueryRow(`SELECT id FROM spaces WHERE invite_code = ?`, inviteCode).Scan(&spaceID)
-	if err != nil {
-		return nil, errors.New("Ungültiger Einladungscode")
-	}
-
-	_, err = s.db.Exec(
-		`INSERT OR IGNORE INTO space_members (space_id, user_id, role, joined_at) VALUES (?, ?, 'editor', ?)`,
-		spaceID, userID, domain.NowISO(),
-	)
-	if err != nil {
-		return nil, err
-	}
-	return s.GetSpaceByID(spaceID)
-}
-
-func (s *Store) GetSpaceByID(spaceID string) (*domain.Space, error) {
-	sp := &domain.Space{}
-	var personalInt int
-	err := s.db.QueryRow(
-		`SELECT id, name, icon, description, invite_code, is_personal, owner_id, created_at FROM spaces WHERE id = ?`,
-		spaceID,
-	).Scan(&sp.ID, &sp.Name, &sp.Icon, &sp.Description, &sp.InviteCode, &personalInt, &sp.OwnerID, &sp.CreatedAt)
-	if err != nil {
-		return nil, err
-	}
-	sp.IsPersonal = personalInt != 0
-	sp.Members, _ = s.GetSpaceMembers(spaceID)
-	_ = s.db.QueryRow(`SELECT COUNT(*) FROM lists WHERE space_id = ?`, spaceID).Scan(&sp.ListsCount)
-	return sp, nil
-}
-
-func (s *Store) GetSpaceMembers(spaceID string) ([]domain.SpaceMember, error) {
-	rows, err := s.db.Query(
-		`SELECT sm.space_id, sm.user_id, u.display_name, u.email, sm.role, sm.joined_at
-		 FROM space_members sm
-		 JOIN users u ON u.id = sm.user_id
-		 WHERE sm.space_id = ?
-		 ORDER BY sm.joined_at ASC`,
-		spaceID,
-	)
-	if err != nil {
-		return nil, err
-	}
-	defer rows.Close()
-
-	members := make([]domain.SpaceMember, 0)
-	for rows.Next() {
-		var m domain.SpaceMember
-		if err := rows.Scan(&m.SpaceID, &m.UserID, &m.DisplayName, &m.Email, &m.Role, &m.JoinedAt); err == nil {
-			members = append(members, m)
-		}
-	}
-	return members, nil
-}
-
-func (s *Store) AddSpaceMember(currentUserID, spaceID, targetUserIdentifier, role string) (*domain.SpaceMember, error) {
-	// 1. Check if current user is member of space
-	var myRole string
-	err := s.db.QueryRow(`SELECT role FROM space_members WHERE space_id = ? AND user_id = ?`, spaceID, currentUserID).Scan(&myRole)
-	if err != nil {
-		return nil, errors.New("keine Berechtigung für diesen Bereich")
-	}
-
-	// 2. Resolve target user by ID, username or email
-	cleanTarget := strings.TrimSpace(targetUserIdentifier)
-	var targetUser *domain.User
-	if strings.HasPrefix(cleanTarget, "usr_") {
-		targetUser, _ = s.GetUserByID(cleanTarget)
-	}
-	if targetUser == nil {
-		targetUser, _ = s.GetUserByLogin(cleanTarget)
-	}
-	if targetUser == nil {
-		targetUser, err = s.GetUserByID(cleanTarget)
-	}
-	if err != nil || targetUser == nil {
-		return nil, errors.New("benutzer nicht gefunden")
-	}
-
-	// Protect existing owner from role downgrade!
-	var existingRole string
-	_ = s.db.QueryRow(`SELECT role FROM space_members WHERE space_id = ? AND user_id = ?`, spaceID, targetUser.ID).Scan(&existingRole)
-	if existingRole == "owner" {
-		role = "owner"
-	} else if role != "owner" && role != "editor" && role != "viewer" {
-		role = "editor"
-	}
-
-	now := domain.NowISO()
-	_, err = s.db.Exec(
-		`INSERT INTO space_members (space_id, user_id, role, joined_at) VALUES (?, ?, ?, ?)
-		 ON CONFLICT(space_id, user_id) DO UPDATE SET role = excluded.role`,
-		spaceID, targetUser.ID, role, now,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	return &domain.SpaceMember{
-		SpaceID:     spaceID,
-		UserID:      targetUser.ID,
-		DisplayName: targetUser.DisplayName,
-		Email:       targetUser.Email,
-		Role:        role,
-		JoinedAt:    now,
-	}, nil
-}
-
-func (s *Store) CreateSpaceTeamShare(currentUserID, spaceID, teamID, role string) (*domain.SpaceShare, error) {
-	var myRole string
-	err := s.db.QueryRow(`SELECT role FROM space_members WHERE space_id = ? AND user_id = ?`, spaceID, currentUserID).Scan(&myRole)
-	if err != nil || (myRole != "owner" && myRole != "editor") {
-		return nil, errors.New("keine Berechtigung für diesen Bereich")
-	}
-
-	cleanTeamID := strings.TrimSpace(teamID)
-	var teamName string
-	err = s.db.QueryRow(`SELECT name FROM teams WHERE id = ?`, cleanTeamID).Scan(&teamName)
-	if err != nil {
-		return nil, errors.New("team nicht gefunden")
-	}
-
-	if role != "owner" && role != "editor" && role != "viewer" {
-		role = "editor"
-	}
-
-	now := domain.NowISO()
-	shareID := domain.NewID("spshare")
-	_, err = s.db.Exec(
-		`INSERT INTO space_team_shares (id, space_id, team_id, role, created_at, created_by)
-		 VALUES (?, ?, ?, ?, ?, ?)
-		 ON CONFLICT(space_id, team_id) DO UPDATE SET role = excluded.role`,
-		shareID, spaceID, cleanTeamID, role, now, currentUserID,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	return &domain.SpaceShare{
-		ID:         shareID,
-		SpaceID:    spaceID,
-		TargetType: "team",
-		TargetID:   cleanTeamID,
-		TargetName: teamName,
-		Role:       role,
-		CreatedBy:  currentUserID,
-		CreatedAt:  now,
-	}, nil
-}
-
-func (s *Store) GetSpaceShares(spaceID string) ([]domain.SpaceShare, error) {
-	shares := make([]domain.SpaceShare, 0)
-
-	// 1. Team shares
-	tRows, err := s.db.Query(
-		`SELECT s.id, s.space_id, s.team_id, t.name, s.role, s.created_by, s.created_at
-		 FROM space_team_shares s
-		 JOIN teams t ON s.team_id = t.id
-		 WHERE s.space_id = ?
-		 ORDER BY s.created_at ASC`,
-		spaceID,
-	)
-	if err == nil {
-		for tRows.Next() {
-			var sh domain.SpaceShare
-			if err := tRows.Scan(&sh.ID, &sh.SpaceID, &sh.TargetID, &sh.TargetName, &sh.Role, &sh.CreatedBy, &sh.CreatedAt); err == nil {
-				sh.TargetType = "team"
-				shares = append(shares, sh)
-			}
-		}
-		_ = tRows.Close()
-	}
-
-	// 2. Individual invited members (non-owner members)
-	var ownerID string
-	_ = s.db.QueryRow(`SELECT owner_id FROM spaces WHERE id = ?`, spaceID).Scan(&ownerID)
-
-	mRows, err := s.db.Query(
-		`SELECT sm.user_id, u.display_name, u.email, sm.role, sm.joined_at
-		 FROM space_members sm
-		 JOIN users u ON u.id = sm.user_id
-		 WHERE sm.space_id = ? AND sm.user_id != ?
-		 ORDER BY sm.joined_at ASC`,
-		spaceID, ownerID,
-	)
-	if err == nil {
-		for mRows.Next() {
-			var uid, dName, email, role, joinedAt string
-			if err := mRows.Scan(&uid, &dName, &email, &role, &joinedAt); err == nil {
-				name := dName
-				if name == "" {
-					name = email
-				}
-				shares = append(shares, domain.SpaceShare{
-					ID:         "sm_" + uid,
-					SpaceID:    spaceID,
-					TargetType: "user",
-					TargetID:   uid,
-					TargetName: name,
-					Role:       role,
-					CreatedAt:  joinedAt,
-				})
-			}
-		}
-		_ = mRows.Close()
-	}
-
-	return shares, nil
-}
-
-func (s *Store) RemoveSpaceTeamShare(currentUserID, spaceID, targetID string) error {
-	var myRole string
-	err := s.db.QueryRow(`SELECT role FROM space_members WHERE space_id = ? AND user_id = ?`, spaceID, currentUserID).Scan(&myRole)
-	if err != nil || (myRole != "owner" && myRole != "editor") {
-		return errors.New("keine Berechtigung zum Entfernen der Freigabe")
-	}
-
-	cleanTarget := strings.TrimSpace(targetID)
-	_, err = s.db.Exec(`DELETE FROM space_team_shares WHERE space_id = ? AND (id = ? OR team_id = ?)`, spaceID, cleanTarget, cleanTarget)
-	return err
-}
-
-func (s *Store) RemoveSpaceMember(currentUserID, spaceID, targetUserID string) error {
-	var myRole string
-	err := s.db.QueryRow(`SELECT role FROM space_members WHERE space_id = ? AND user_id = ?`, spaceID, currentUserID).Scan(&myRole)
-	if err != nil {
-		return errors.New("keine Berechtigung für diesen Bereich")
-	}
-
-	cleanTarget := strings.TrimSpace(targetUserID)
-	if strings.HasPrefix(cleanTarget, "team_") || strings.HasPrefix(cleanTarget, "spshare_") {
-		return s.RemoveSpaceTeamShare(currentUserID, spaceID, cleanTarget)
-	}
-
-	if currentUserID != cleanTarget && myRole != "owner" {
-		return errors.New("nur der Eigentümer kann andere Mitglieder entfernen")
-	}
-
-	var targetRole string
-	_ = s.db.QueryRow(`SELECT role FROM space_members WHERE space_id = ? AND user_id = ?`, spaceID, cleanTarget).Scan(&targetRole)
-	if targetRole == "owner" {
-		var ownerCount int
-		_ = s.db.QueryRow(`SELECT COUNT(*) FROM space_members WHERE space_id = ? AND role = 'owner'`, spaceID).Scan(&ownerCount)
-		if ownerCount <= 1 {
-			return errors.New("der letzte Eigentümer kann den Bereich nicht verlassen")
-		}
-	}
-
-	_, err = s.db.Exec(`DELETE FROM space_members WHERE space_id = ? AND user_id = ?`, spaceID, cleanTarget)
-	return err
-}
-
-func (s *Store) GetSpacesForUser(userID string) ([]domain.Space, error) {
-	rows, err := s.db.Query(
-		`SELECT s.id, s.name, s.icon, s.description, s.invite_code, s.is_personal, s.owner_id, s.created_at
-		 FROM spaces s
-		 LEFT JOIN space_members sm ON sm.space_id = s.id AND sm.user_id = ?
-		 LEFT JOIN space_team_shares sts ON sts.space_id = s.id AND sts.team_id IN (SELECT team_id FROM team_members WHERE user_id = ?)
-		 WHERE sm.user_id = ? OR sts.team_id IS NOT NULL
-		 GROUP BY s.id
-		 ORDER BY s.created_at ASC`,
-		userID, userID, userID,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	spaces := make([]domain.Space, 0)
-	for rows.Next() {
-		var sp domain.Space
-		var personalInt int
-		if err := rows.Scan(&sp.ID, &sp.Name, &sp.Icon, &sp.Description, &sp.InviteCode, &personalInt, &sp.OwnerID, &sp.CreatedAt); err == nil {
-			sp.IsPersonal = personalInt != 0
-			spaces = append(spaces, sp)
-		}
-	}
-	_ = rows.Close()
-
-	for i := range spaces {
-		spaces[i].Members, _ = s.GetSpaceMembers(spaces[i].ID)
-		spaces[i].Shares, _ = s.GetSpaceShares(spaces[i].ID)
-		_ = s.db.QueryRow(`SELECT COUNT(*) FROM lists WHERE space_id = ?`, spaces[i].ID).Scan(&spaces[i].ListsCount)
-	}
-	return spaces, nil
-}
-
-func (s *Store) CreateList(spaceID, title, icon, listType string) (*domain.SharedList, error) {
+func (s *Store) CreateList(userID, title, icon, listType string) (*domain.SharedList, error) {
 	if strings.TrimSpace(title) == "" {
 		return nil, errors.New("list title required")
 	}
@@ -2535,59 +2197,167 @@ func (s *Store) CreateList(spaceID, title, icon, listType string) (*domain.Share
 	now := domain.NowISO()
 	lst := &domain.SharedList{
 		ID:        domain.NewID("lst"),
-		SpaceID:   spaceID,
+		UserID:    userID,
+		IsOwner:   true,
+		Role:      "editor",
 		Title:     strings.TrimSpace(title),
 		Icon:      icon,
 		ListType:  listType,
 		Items:     []domain.ListItem{},
+		Shares:    []domain.ListShare{},
 		UpdatedAt: now,
 		CreatedAt: now,
 	}
 
 	_, err := s.db.Exec(
-		`INSERT INTO lists (id, space_id, title, icon, list_type, updated_at, created_at) VALUES (?, ?, ?, ?, ?, ?, ?)`,
-		lst.ID, lst.SpaceID, lst.Title, lst.Icon, lst.ListType, lst.UpdatedAt, lst.CreatedAt,
+		`INSERT INTO lists (id, user_id, title, icon, list_type, updated_at, created_at) VALUES (?, ?, ?, ?, ?, ?, ?)`,
+		lst.ID, lst.UserID, lst.Title, lst.Icon, lst.ListType, lst.UpdatedAt, lst.CreatedAt,
 	)
 	if err != nil {
 		return nil, err
 	}
+	_ = s.db.QueryRow(`SELECT display_name FROM users WHERE id = ?`, userID).Scan(&lst.OwnerName)
 	return lst, nil
 }
 
-func (s *Store) GetListsForSpace(spaceID string) ([]domain.SharedList, error) {
-	rows, err := s.db.Query(
-		`SELECT id, space_id, title, icon, list_type, updated_at, created_at
-		 FROM lists WHERE space_id = ? ORDER BY created_at ASC`,
-		spaceID,
+func (s *Store) AddListShare(currentUserID, listID, targetType, targetID, role string) (*domain.ListShare, error) {
+	if targetType != "team" && targetType != "user" {
+		return nil, errors.New("ungültiger Freigabetyp")
+	}
+	targetID = strings.TrimSpace(targetID)
+	if targetID == "" {
+		return nil, errors.New("Ziel-ID erforderlich")
+	}
+	if role != "viewer" && role != "editor" {
+		role = "editor"
+	}
+
+	if targetType == "user" {
+		var targetUser *domain.User
+		if strings.HasPrefix(targetID, "usr_") {
+			targetUser, _ = s.GetUserByID(targetID)
+		}
+		if targetUser == nil {
+			targetUser, _ = s.GetUserByLogin(targetID)
+		}
+		if targetUser == nil {
+			targetUser, _ = s.GetUserByEmail(targetID)
+		}
+		if targetUser == nil {
+			return nil, fmt.Errorf("benutzer nicht gefunden: %s", targetID)
+		}
+		targetID = targetUser.ID
+	}
+
+	// Verify current user is owner or editor of the list
+	var ownerID string
+	err := s.db.QueryRow(`SELECT user_id FROM lists WHERE id = ?`, listID).Scan(&ownerID)
+	if err != nil {
+		return nil, errors.New("liste nicht gefunden")
+	}
+	if ownerID != currentUserID {
+		var myRole string
+		err = s.db.QueryRow(`SELECT role FROM list_shares WHERE list_id = ? AND target_type = 'user' AND target_id = ?`, listID, currentUserID).Scan(&myRole)
+		if err != nil || myRole != "editor" {
+			return nil, errors.New("keine Berechtigung zum Teilen dieser Liste")
+		}
+	}
+
+	now := domain.NowISO()
+	share := &domain.ListShare{
+		ID:         domain.NewID("lsh"),
+		ListID:     listID,
+		TargetType: targetType,
+		TargetID:   targetID,
+		Role:       role,
+		CreatedBy:  currentUserID,
+		CreatedAt:  now,
+	}
+
+	_, err = s.db.Exec(
+		`INSERT INTO list_shares (id, list_id, target_type, target_id, role, created_by, created_at)
+		 VALUES (?, ?, ?, ?, ?, ?, ?)
+		 ON CONFLICT(list_id, target_type, target_id) DO UPDATE SET role = excluded.role`,
+		share.ID, share.ListID, share.TargetType, share.TargetID, share.Role, share.CreatedBy, share.CreatedAt,
 	)
 	if err != nil {
 		return nil, err
 	}
 
-	lists := make([]domain.SharedList, 0)
+	_ = s.db.QueryRow(`SELECT id, created_at FROM list_shares WHERE list_id = ? AND target_type = ? AND target_id = ?`,
+		listID, targetType, targetID).Scan(&share.ID, &share.CreatedAt)
+
+	if targetType == "team" {
+		_ = s.db.QueryRow(`SELECT name FROM teams WHERE id = ?`, targetID).Scan(&share.TargetName)
+	} else {
+		_ = s.db.QueryRow(`SELECT display_name, email FROM users WHERE id = ?`, targetID).Scan(&share.TargetName, &share.Email)
+	}
+	return share, nil
+}
+
+func (s *Store) RemoveListShare(currentUserID, listID, shareIDOrTargetID string) error {
+	var ownerID string
+	err := s.db.QueryRow(`SELECT user_id FROM lists WHERE id = ?`, listID).Scan(&ownerID)
+	if err != nil {
+		return errors.New("liste nicht gefunden")
+	}
+	if ownerID != currentUserID {
+		return errors.New("nur der Eigentümer kann Freigaben entfernen")
+	}
+
+	cleanTarget := strings.TrimSpace(shareIDOrTargetID)
+	_, err = s.db.Exec(
+		`DELETE FROM list_shares WHERE list_id = ? AND (id = ? OR target_id = ?)`,
+		listID, cleanTarget, cleanTarget,
+	)
+	return err
+}
+
+func (s *Store) GetListShares(listID string) ([]domain.ListShare, error) {
+	rows, err := s.db.Query(
+		`SELECT id, list_id, target_type, target_id, role, created_by, created_at
+		 FROM list_shares WHERE list_id = ? ORDER BY created_at ASC`,
+		listID,
+	)
+	if err != nil {
+		return []domain.ListShare{}, err
+	}
+	defer rows.Close()
+
+	shares := make([]domain.ListShare, 0)
 	for rows.Next() {
-		var l domain.SharedList
-		if err := rows.Scan(&l.ID, &l.SpaceID, &l.Title, &l.Icon, &l.ListType, &l.UpdatedAt, &l.CreatedAt); err == nil {
-			lists = append(lists, l)
+		var sh domain.ListShare
+		if err := rows.Scan(&sh.ID, &sh.ListID, &sh.TargetType, &sh.TargetID, &sh.Role, &sh.CreatedBy, &sh.CreatedAt); err == nil {
+			if sh.TargetType == "team" {
+				_ = s.db.QueryRow(`SELECT name FROM teams WHERE id = ?`, sh.TargetID).Scan(&sh.TargetName)
+			} else {
+				_ = s.db.QueryRow(`SELECT display_name, email FROM users WHERE id = ?`, sh.TargetID).Scan(&sh.TargetName, &sh.Email)
+			}
+			shares = append(shares, sh)
 		}
 	}
-	_ = rows.Close()
-
-	for i := range lists {
-		lists[i].Items, _ = s.GetListItems(lists[i].ID)
-	}
-	return lists, nil
+	return shares, nil
 }
 
 func (s *Store) GetAllListsForUser(userID string) ([]domain.SharedList, error) {
 	rows, err := s.db.Query(
-		`SELECT DISTINCT l.id, l.space_id, l.title, l.icon, l.list_type, l.updated_at, l.created_at
+		`SELECT DISTINCT l.id, l.user_id, l.title, l.icon, l.list_type, l.updated_at, l.created_at,
+		        u.display_name,
+		        CASE 
+		            WHEN l.user_id = ? THEN 'owner'
+		            WHEN ls.role IS NOT NULL THEN ls.role
+		            ELSE 'editor'
+		        END as effective_role
 		 FROM lists l
-		 LEFT JOIN space_members sm ON sm.space_id = l.space_id AND sm.user_id = ?
-		 LEFT JOIN space_team_shares sts ON sts.space_id = l.space_id AND sts.team_id IN (SELECT team_id FROM team_members WHERE user_id = ?)
-		 WHERE sm.user_id = ? OR sts.team_id IS NOT NULL
+		 LEFT JOIN users u ON u.id = l.user_id
+		 LEFT JOIN list_shares ls ON ls.list_id = l.id AND (
+		     (ls.target_type = 'user' AND ls.target_id = ?)
+		     OR (ls.target_type = 'team' AND ls.target_id IN (SELECT team_id FROM team_members WHERE user_id = ?))
+		 )
+		 WHERE l.user_id = ?
+		    OR ls.id IS NOT NULL
 		 ORDER BY l.updated_at DESC`,
-		userID, userID, userID,
+		userID, userID, userID, userID,
 	)
 	if err != nil {
 		return nil, err
@@ -2596,7 +2366,12 @@ func (s *Store) GetAllListsForUser(userID string) ([]domain.SharedList, error) {
 	lists := make([]domain.SharedList, 0)
 	for rows.Next() {
 		var l domain.SharedList
-		if err := rows.Scan(&l.ID, &l.SpaceID, &l.Title, &l.Icon, &l.ListType, &l.UpdatedAt, &l.CreatedAt); err == nil {
+		var ownerName sql.NullString
+		var effectiveRole string
+		if err := rows.Scan(&l.ID, &l.UserID, &l.Title, &l.Icon, &l.ListType, &l.UpdatedAt, &l.CreatedAt, &ownerName, &effectiveRole); err == nil {
+			l.OwnerName = ownerName.String
+			l.IsOwner = (l.UserID == userID)
+			l.Role = effectiveRole
 			lists = append(lists, l)
 		}
 	}
@@ -2604,25 +2379,68 @@ func (s *Store) GetAllListsForUser(userID string) ([]domain.SharedList, error) {
 
 	for i := range lists {
 		lists[i].Items, _ = s.GetListItems(lists[i].ID)
+		lists[i].Shares, _ = s.GetListShares(lists[i].ID)
 	}
 	return lists, nil
 }
 
-func (s *Store) GetListByID(listID string) (*domain.SharedList, error) {
+func (s *Store) GetListByID(userID, listID string) (*domain.SharedList, error) {
 	var l domain.SharedList
-	err := s.db.QueryRow(
-		`SELECT id, space_id, title, icon, list_type, updated_at, created_at FROM lists WHERE id = ?`,
-		listID,
-	).Scan(&l.ID, &l.SpaceID, &l.Title, &l.Icon, &l.ListType, &l.UpdatedAt, &l.CreatedAt)
+	var ownerName sql.NullString
+	var effectiveRole string
+
+	var query string
+	var args []interface{}
+	if userID == "" {
+		query = `SELECT l.id, l.user_id, l.title, l.icon, l.list_type, l.updated_at, l.created_at,
+		        u.display_name, 'owner' as effective_role
+		 FROM lists l
+		 LEFT JOIN users u ON u.id = l.user_id
+		 WHERE l.id = ?`
+		args = []interface{}{listID}
+	} else {
+		query = `SELECT l.id, l.user_id, l.title, l.icon, l.list_type, l.updated_at, l.created_at,
+		        u.display_name,
+		        CASE 
+		            WHEN l.user_id = ? THEN 'owner'
+		            WHEN ls.role IS NOT NULL THEN ls.role
+		            ELSE 'editor'
+		        END as effective_role
+		 FROM lists l
+		 LEFT JOIN users u ON u.id = l.user_id
+		 LEFT JOIN list_shares ls ON ls.list_id = l.id AND (
+		     (ls.target_type = 'user' AND ls.target_id = ?)
+		     OR (ls.target_type = 'team' AND ls.target_id IN (SELECT team_id FROM team_members WHERE user_id = ?))
+		 )
+		 WHERE l.id = ? AND (
+		     l.user_id = ?
+		     OR ls.id IS NOT NULL
+		 )`
+		args = []interface{}{userID, userID, userID, listID, userID}
+	}
+
+	err := s.db.QueryRow(query, args...).Scan(&l.ID, &l.UserID, &l.Title, &l.Icon, &l.ListType, &l.UpdatedAt, &l.CreatedAt, &ownerName, &effectiveRole)
 	if err != nil {
 		return nil, err
 	}
+	l.OwnerName = ownerName.String
+	l.IsOwner = (userID == "" || l.UserID == userID)
+	l.Role = effectiveRole
 	l.Items, _ = s.GetListItems(l.ID)
+	l.Shares, _ = s.GetListShares(l.ID)
 	return &l, nil
 }
 
-func (s *Store) DeleteList(listID string) error {
-	_, err := s.db.Exec(`DELETE FROM lists WHERE id = ?`, listID)
+func (s *Store) DeleteList(userID, listID string) error {
+	var ownerID string
+	err := s.db.QueryRow(`SELECT user_id FROM lists WHERE id = ?`, listID).Scan(&ownerID)
+	if err != nil {
+		return errors.New("liste nicht gefunden")
+	}
+	if ownerID != userID {
+		return errors.New("nur der Eigentümer kann die Liste löschen")
+	}
+	_, err = s.db.Exec(`DELETE FROM lists WHERE id = ?`, listID)
 	return err
 }
 
@@ -2829,9 +2647,11 @@ func (s *Store) GetDashboardStats(userID string) (*domain.DashboardStats, error)
 	_ = s.db.QueryRow(`
 		SELECT COUNT(DISTINCT l.id) 
 		FROM lists l 
-		LEFT JOIN space_members sm ON sm.space_id = l.space_id AND sm.user_id = ?
-		LEFT JOIN space_team_shares sts ON sts.space_id = l.space_id AND sts.team_id IN (SELECT team_id FROM team_members WHERE user_id = ?)
-		WHERE sm.user_id = ? OR sts.team_id IS NOT NULL`,
+		LEFT JOIN list_shares ls ON ls.list_id = l.id AND (
+		    (ls.target_type = 'user' AND ls.target_id = ?)
+		    OR (ls.target_type = 'team' AND ls.target_id IN (SELECT team_id FROM team_members WHERE user_id = ?))
+		)
+		WHERE l.user_id = ? OR ls.id IS NOT NULL`,
 		userID, userID, userID).Scan(&st.ListsCount)
 
 	// Count open (uncompleted) To-Dos across accessible workspace documents (owned or shared)
@@ -2908,7 +2728,6 @@ func (s *Store) ExportUserData(userID string) (*domain.FullExport, error) {
 	}
 	thoughts, _ := s.GetThoughts(userID, "all", 5000)
 	docs, _ := s.GetDocuments(userID)
-	spaces, _ := s.GetSpacesForUser(userID)
 	lists, _ := s.GetAllListsForUser(userID)
 	taskLists, _ := s.GetTaskLists(userID)
 
@@ -2918,7 +2737,6 @@ func (s *Store) ExportUserData(userID string) (*domain.FullExport, error) {
 		User:       *user,
 		Thoughts:   thoughts,
 		Documents:  docs,
-		Spaces:     spaces,
 		Lists:      lists,
 		TaskLists:  taskLists,
 	}, nil
@@ -3127,9 +2945,8 @@ func (s *Store) GetTaskLists(userID string) ([]domain.TaskList, error) {
 		        WHERE (target_type = 'user' AND target_id = ?) 
 		           OR (target_type = 'team' AND target_id IN (SELECT team_id FROM team_members WHERE user_id = ?))
 		    )
-		    OR (space_id != '' AND space_id IN (SELECT space_id FROM space_members WHERE user_id = ?))
 		 ORDER BY updated_at DESC`,
-		userID, userID, userID, userID, userID,
+		userID, userID, userID, userID,
 	)
 	if err != nil {
 		return []domain.TaskList{}, err
@@ -3192,9 +3009,8 @@ func (s *Store) GetTaskListByID(userID, listID string) (*domain.TaskList, error)
 		        WHERE (target_type = 'user' AND target_id = ?) 
 		           OR (target_type = 'team' AND target_id IN (SELECT team_id FROM team_members WHERE user_id = ?))
 		    )
-		    OR (space_id != '' AND space_id IN (SELECT space_id FROM space_members WHERE user_id = ?))
 		 )`,
-		listID, userID, userID, userID, userID, userID,
+		listID, userID, userID, userID, userID,
 	).Scan(&tl.ID, &tl.UserID, &tl.SpaceID, &tl.TeamID, &tl.Title, &tl.Icon, &tl.Color, &colsJSON, &tl.CreatedAt, &tl.UpdatedAt)
 	if err != nil {
 		return nil, err

internal/storage/sqlite_test.go

@@ -48,12 +48,8 @@ func TestStoreLifecycle(t *testing.T) {
 		t.Fatalf("expected converted document, got status=%s type=%s ref=%s", triaged.Status, triaged.ConvertedType, triaged.ConvertedRefID)
 	}
 
-	// 3. Test Shared Space & Shopping List
-	sp, err := store.CreateSpace(user.ID, "Test WG", "🍕", "Test Space", false)
-	if err != nil {
-		t.Fatalf("CreateSpace failed: %v", err)
-	}
-	lst, err := store.CreateList(sp.ID, "REWE Einkauf", "🛒", "shopping")
+	// 3. Test Standalone Shopping List & Sharing
+	lst, err := store.CreateList(user.ID, "REWE Einkauf", "🛒", "shopping")
 	if err != nil {
 		t.Fatalf("CreateList failed: %v", err)
 	}
@@ -66,26 +62,26 @@ func TestStoreLifecycle(t *testing.T) {
 		t.Fatalf("ToggleListItem failed: %v", err)
 	}
 
-	// Test AddSpaceMember & RemoveSpaceMember
+	// Test AddListShare & RemoveListShare
 	u2, err := store.CreateUser("collab_space@example.com", "hash", "Collab User", "member")
 	if err != nil {
 		t.Fatalf("CreateUser u2 failed: %v", err)
 	}
-	member, err := store.AddSpaceMember(user.ID, sp.ID, u2.ID, "editor")
-	if err != nil || member.UserID != u2.ID {
-		t.Fatalf("AddSpaceMember failed: %v", err)
+	share, err := store.AddListShare(user.ID, lst.ID, "user", u2.ID, "editor")
+	if err != nil || share.TargetID != u2.ID {
+		t.Fatalf("AddListShare failed: %v", err)
 	}
-	members, err := store.GetSpaceMembers(sp.ID)
-	if err != nil || len(members) != 2 {
-		t.Fatalf("expected 2 members, got %d", len(members))
+	shares, err := store.GetListShares(lst.ID)
+	if err != nil || len(shares) != 1 {
+		t.Fatalf("expected 1 share, got %d", len(shares))
 	}
-	err = store.RemoveSpaceMember(user.ID, sp.ID, u2.ID)
+	err = store.RemoveListShare(user.ID, lst.ID, share.ID)
 	if err != nil {
-		t.Fatalf("RemoveSpaceMember failed: %v", err)
+		t.Fatalf("RemoveListShare failed: %v", err)
 	}
-	membersAfter, _ := store.GetSpaceMembers(sp.ID)
-	if len(membersAfter) != 1 {
-		t.Fatalf("expected 1 member after remove, got %d", len(membersAfter))
+	sharesAfter, _ := store.GetListShares(lst.ID)
+	if len(sharesAfter) != 0 {
+		t.Fatalf("expected 0 shares after remove, got %d", len(sharesAfter))
 	}
 
 	// 4. Test Webhook API Key generation & validation
@@ -99,7 +95,7 @@ func TestStoreLifecycle(t *testing.T) {
 	}
 
 	// 5. Test TaskLists CRUD
-	taskList, err := store.CreateTaskList(user.ID, sp.ID, "", "Haus & Garten", "🏡", "#10b981")
+	taskList, err := store.CreateTaskList(user.ID, "", "", "Haus & Garten", "🏡", "#10b981")
 	if err != nil || taskList.ID == "" {
 		t.Fatalf("CreateTaskList failed: %v", err)
 	}
@@ -160,8 +156,8 @@ func TestStoreLifecycle(t *testing.T) {
 	}
 
 	// Share with user2 as "read"
-	share, err := store.CreateDocShare(user.ID, newDoc.ID, user2.ID, "read")
-	if err != nil || share.Permission != "read" {
+	docShare, err := store.CreateDocShare(user.ID, newDoc.ID, user2.ID, "read")
+	if err != nil || docShare.Permission != "read" {
 		t.Fatalf("CreateDocShare failed: %v", err)
 	}