feat: add user preferences dashboard

- Add /preferences route and preferences.html template for user settings
- Implement username, email, password, and theme update functionality
- Add account deletion feature with confirmation
- Add navigation link to preferences from dashboard
- Create API endpoints:
  - PUT /api/user/username - Update username
  - PUT /api/user/email - Update email address
  - PUT /api/user/password - Change password with verification
  - DELETE /api/user/account - Delete user account
- Add database queries for user updates and account deletion
- Create Bruno API testing files for all user preference endpoints
- Add proper validation, error handling, and security checks

internal/database/queries.sql.go

@@ -198,6 +198,15 @@ func (q *Queries) DeleteReadingProgress(ctx context.Context, arg DeleteReadingPr
 	return err
 }
 
+const DeleteUser = `-- name: DeleteUser :exec
+DELETE FROM users WHERE id = $1
+`
+
+func (q *Queries) DeleteUser(ctx context.Context, id pgtype.UUID) error {
+	_, err := q.db.Exec(ctx, DeleteUser, id)
+	return err
+}
+
 const DeleteUserEbookFolder = `-- name: DeleteUserEbookFolder :exec
 DELETE FROM user_ebook_folders WHERE user_id = $1 AND folder_path = $2
 `
@@ -477,6 +486,17 @@ func (q *Queries) GetUserEbookFolders(ctx context.Context, userID pgtype.UUID) (
 	return items, nil
 }
 
+const GetUserPasswordHash = `-- name: GetUserPasswordHash :one
+SELECT password_hash FROM users WHERE id = $1
+`
+
+func (q *Queries) GetUserPasswordHash(ctx context.Context, id pgtype.UUID) (string, error) {
+	row := q.db.QueryRow(ctx, GetUserPasswordHash, id)
+	var password_hash string
+	err := row.Scan(&password_hash)
+	return password_hash, err
+}
+
 const ListEbooks = `-- name: ListEbooks :many
 SELECT id, title, author, isbn, description, file_path, file_size, mime_type, cover_image_path, created_at, updated_at, series, series_number, tags, asin, date_published, publisher, contributors FROM ebooks ORDER BY created_at DESC LIMIT $1 OFFSET $2
 `
@@ -668,6 +688,34 @@ func (q *Queries) UpdateEbookRating(ctx context.Context, arg UpdateEbookRatingPa
 	return i, err
 }
 
+const UpdateEmail = `-- name: UpdateEmail :exec
+UPDATE users SET email = $2, updated_at = NOW() WHERE id = $1
+`
+
+type UpdateEmailParams struct {
+	ID    pgtype.UUID `db:"id" json:"id"`
+	Email string      `db:"email" json:"email"`
+}
+
+func (q *Queries) UpdateEmail(ctx context.Context, arg UpdateEmailParams) error {
+	_, err := q.db.Exec(ctx, UpdateEmail, arg.ID, arg.Email)
+	return err
+}
+
+const UpdatePassword = `-- name: UpdatePassword :exec
+UPDATE users SET password_hash = $2, updated_at = NOW() WHERE id = $1
+`
+
+type UpdatePasswordParams struct {
+	ID           pgtype.UUID `db:"id" json:"id"`
+	PasswordHash string      `db:"password_hash" json:"password_hash"`
+}
+
+func (q *Queries) UpdatePassword(ctx context.Context, arg UpdatePasswordParams) error {
+	_, err := q.db.Exec(ctx, UpdatePassword, arg.ID, arg.PasswordHash)
+	return err
+}
+
 const UpdateReadingProgress = `-- name: UpdateReadingProgress :one
 INSERT INTO reading_progress (ebook_id, user_id, current_page, total_pages, last_read_at)
 VALUES ($1, $2, $3, $4, NOW())
@@ -718,3 +766,17 @@ func (q *Queries) UpdateUserTheme(ctx context.Context, arg UpdateUserThemeParams
 	_, err := q.db.Exec(ctx, UpdateUserTheme, arg.ID, arg.Theme)
 	return err
 }
+
+const UpdateUsername = `-- name: UpdateUsername :exec
+UPDATE users SET username = $2, updated_at = NOW() WHERE id = $1
+`
+
+type UpdateUsernameParams struct {
+	ID       pgtype.UUID `db:"id" json:"id"`
+	Username string      `db:"username" json:"username"`
+}
+
+func (q *Queries) UpdateUsername(ctx context.Context, arg UpdateUsernameParams) error {
+	_, err := q.db.Exec(ctx, UpdateUsername, arg.ID, arg.Username)
+	return err
+}