release: v0.2 – collaboration docs, richer demo data, new screenshots

- Turn the collaboration plan into module docs (Doku/modules/collaboration.md)
  describing the implemented state; remove Doku/plans
- Header version comes from the build: git tag via APP_VERSION (CI passes
  it for tag builds), otherwise "<package version>-dev"; package 0.2.0
- Sample data (setup option and demo mode): six inbox thoughts, two task
  lists with Kanban states, subtasks and due dates, shopping and packing
  lists, three notes in folders incl. a long nested outline; demo mode
  shares the note and two lists with user/user
- e2e/screenshots.sh renews the README screenshots from demo data
- README: live collaboration, editor sharing, image tags, version badge

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

internal/storage/sqlite.go

@@ -474,58 +474,6 @@ func (s *Store) migrate() error {
 	return nil
 }
 
-// SeedStarterContent populates realistic initial content for a newly created user if requested
-func (s *Store) SeedStarterContent(user *domain.User) error {
-	now := domain.NowISO()
-
-	starterThoughts := []struct {
-		content  string
-		priority string
-		source   string
-		dueDate  string
-	}{
-		{
-			content:  "Zündkerzen und Luftfilter für den Rasenmäher bestellen #garage #wartung",
-			priority: "normal",
-			source:   "manual",
-		},
-		{
-			content:  "Urlaubsidee: Wanderhütte in Südtirol für Oktober buchen #urlaub #familie",
-			priority: "high",
-			source:   "voice",
-		},
-		{
-			content:  "Kellerfeuchtigkeit über 68% gestiegen – Entfeuchter prüfen #smarthome #alarm",
-			priority: "urgent",
-			source:   "webhook",
-		},
-	}
-
-	for _, st := range starterThoughts {
-		_, _ = s.CreateThought(user.ID, st.content, st.priority, st.source, st.dueDate)
-	}
-
-	keptTask, err := s.CreateThought(user.ID, "Gitea CI/CD Pipeline für MindSift Container testen #devops #docker", "high", "manual", now[:10])
-	if err == nil && keptTask != nil {
-		_, _ = s.UpdateThoughtTriage(user.ID, keptTask.ID, "keep", "task", "", now[:10], "")
-	}
-
-	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{
-		{ID: "blk_1", Type: "callout", Content: "Willkommen in deinem MindSift Workspace! Hier wachsen flüchtige Gedanken aus deiner Inbox zu strukturierten Projekten heran."},
-		{ID: "blk_2", Type: "h2", Content: "Projekt-Checkliste"},
-		{ID: "blk_3", Type: "todo", Content: "MindSift als Docker-Container auf eigenem Server starten", Checked: true},
-	}
-
-	_, _ = s.CreateDocument(user.ID, "", "MindSift Architektur & Notizen", "🚀", "", starterBlocks, []string{"mindsift", "workflow"}, true)
-	return nil
-}
-
 // EnsureDefaultUser is retained strictly for unit test convenience
 func (s *Store) EnsureDefaultUser() (*domain.User, error) {
 	s.initMu.Lock()
@@ -679,13 +627,14 @@ func (s *Store) EnsureDemoAccounts() error {
 	}
 
 	// 1. Admin user (admin / admin)
+	adminCreated := false
 	adminUser, err := s.GetUserByLogin("admin")
 	if err != nil || adminUser == nil {
 		adminUser, err = s.CreateUserWithUsername("admin@mindsift.local", "admin", adminHash, "Admin", "admin")
 		if err != nil {
 			return fmt.Errorf("failed to create demo admin: %w", err)
 		}
-		_ = s.SeedStarterContent(adminUser)
+		adminCreated = true
 	} else {
 		_ = s.UpdateUserPassword(adminUser.ID, adminHash)
 		_, _ = s.db.Exec(`UPDATE users SET is_active = 1, role = 'admin' WHERE id = ?`, adminUser.ID)
@@ -694,7 +643,7 @@ func (s *Store) EnsureDemoAccounts() error {
 	// 2. Regular user (user / user)
 	normalUser, err := s.GetUserByLogin("user")
 	if err != nil || normalUser == nil {
-		_, err = s.CreateUserWithUsername("user@mindsift.local", "user", userHash, "User", "member")
+		normalUser, err = s.CreateUserWithUsername("user@mindsift.local", "user", userHash, "User", "member")
 		if err != nil {
 			return fmt.Errorf("failed to create demo user: %w", err)
 		}
@@ -703,6 +652,12 @@ func (s *Store) EnsureDemoAccounts() error {
 		_, _ = s.db.Exec(`UPDATE users SET is_active = 1 WHERE id = ?`, normalUser.ID)
 	}
 
+	// 3. Sample data for the admin, partly shared with the demo user (only on first start)
+	if adminCreated {
+		_ = s.SeedStarterContent(adminUser)
+		s.seedDemoShares(adminUser, normalUser)
+	}
+
 	return nil
 }