feat: add admin dashboard

apps/server/internal/docs/repository.go

@@ -14,13 +14,22 @@ type Repository struct {
 }
 
 type DocumentRecord struct {
-	ID          string
-	Path        string
-	CurrentHash string
-	Title       string
-	Tags        []string
-	CreatedAt   time.Time
-	UpdatedAt   time.Time
+	ID          string    `json:"id"`
+	Path        string    `json:"path"`
+	CurrentHash string    `json:"currentHash"`
+	Title       string    `json:"title"`
+	Tags        []string  `json:"tags"`
+	CreatedAt   time.Time `json:"createdAt"`
+	UpdatedAt   time.Time `json:"updatedAt"`
+}
+
+type UserRecord struct {
+	ID          string    `json:"id"`
+	Email       string    `json:"email"`
+	DisplayName string    `json:"displayName"`
+	Role        string    `json:"role"`
+	CreatedAt   time.Time `json:"createdAt"`
+	LastSeenAt  time.Time `json:"lastSeenAt,omitempty"`
 }
 
 type AttachmentRecord struct {
@@ -151,6 +160,82 @@ func (r *Repository) ListDocuments(ctx context.Context) ([]DocumentRecord, error
 	return records, rows.Err()
 }
 
+func (r *Repository) ListUsers(ctx context.Context) ([]UserRecord, error) {
+	rows, err := r.db.QueryContext(ctx, `
+		SELECT id, email, COALESCE(display_name, ''), COALESCE(role, 'viewer'), created_at, COALESCE(last_seen_at, '')
+		FROM users
+		ORDER BY created_at DESC
+	`)
+	if err != nil {
+		return nil, fmt.Errorf("list users: %w", err)
+	}
+	defer rows.Close()
+
+	var users []UserRecord
+	for rows.Next() {
+		var (
+			user     UserRecord
+			created  string
+			lastSeen string
+		)
+		if err := rows.Scan(&user.ID, &user.Email, &user.DisplayName, &user.Role, &created, &lastSeen); err != nil {
+			return nil, fmt.Errorf("scan user: %w", err)
+		}
+		createdAt, err := time.Parse(time.RFC3339, created)
+		if err != nil {
+			return nil, fmt.Errorf("parse user created_at: %w", err)
+		}
+		user.CreatedAt = createdAt
+		if lastSeen != "" {
+			parsed, err := time.Parse(time.RFC3339, lastSeen)
+			if err != nil {
+				return nil, fmt.Errorf("parse user last_seen_at: %w", err)
+			}
+			user.LastSeenAt = parsed
+		}
+		users = append(users, user)
+	}
+
+	return users, rows.Err()
+}
+
+func (r *Repository) UpsertUser(ctx context.Context, user UserRecord) (UserRecord, error) {
+	now := time.Now().UTC()
+	if user.ID == "" {
+		user.ID = "user:" + user.Email
+	}
+	if user.Role == "" {
+		user.Role = "viewer"
+	}
+	if user.DisplayName == "" {
+		user.DisplayName = user.Email
+	}
+	user.CreatedAt = now
+	user.LastSeenAt = now
+
+	if _, err := r.db.ExecContext(ctx, `
+		INSERT INTO users (id, email, display_name, role, created_at, last_seen_at)
+		VALUES (?, ?, ?, ?, ?, ?)
+		ON CONFLICT(email) DO UPDATE SET
+			display_name = excluded.display_name,
+			role = excluded.role,
+			last_seen_at = excluded.last_seen_at
+	`, user.ID, user.Email, user.DisplayName, user.Role, now.Format(time.RFC3339), now.Format(time.RFC3339)); err != nil {
+		return UserRecord{}, fmt.Errorf("upsert user %s: %w", user.Email, err)
+	}
+
+	users, err := r.ListUsers(ctx)
+	if err != nil {
+		return UserRecord{}, err
+	}
+	for _, candidate := range users {
+		if candidate.Email == user.Email {
+			return candidate, nil
+		}
+	}
+	return UserRecord{}, sql.ErrNoRows
+}
+
 func (r *Repository) SaveAttachment(ctx context.Context, record AttachmentRecord) error {
 	if _, err := r.db.ExecContext(ctx, `
 		INSERT INTO attachments (hash, original_name, content_type, size_bytes, created_at)