FIX WEB FERTILIZER SUBTYPE UI (CRITICAL) PROBLEM: On the web, when creating or editing a fertilizer listing: - The UI ONLY shows fertilizer_type (organic / chemical) - The fertilizer SUBTYPE (specific fertilizer product) is NOT shown - User cannot select fertilizer subtype - Mobile works correctly, web does not DATABASE IS CORRECT — DO NOT CHANGE DATABASE. SOURCE OF TRUTH (DATABASE RULES): - listings.category = 'fertilizer' - fertilizer_details.fertilizer_type → TEXT ('organic' | 'chemical') - fertilizer_details.fertilizer_type_id → UUID → references fertilizer_types.id - fertilizer_types table contains: - id (UUID) - name_en - name_sw - category ('organic' | 'chemical')