feat(templates): add category-based organization

- Added 'category' column to routine_templates table
- Categorized all 12 templates into: Daily Routines, Getting Things Done, Health & Body, Errands
- Added /api/templates/categories endpoint to list unique categories
- Updated /api/templates to support filtering by category query param
- Redesigned templates page with collapsible accordion sections by category
- Categories are sorted in logical order (Daily → Work → Health → Errands)
- All categories expanded by default for easy browsing

config/schema.sql

@@ -90,6 +90,7 @@ CREATE TABLE IF NOT EXISTS routine_templates (
     name VARCHAR(255) NOT NULL,
     description TEXT,
     icon VARCHAR(100),
+    category VARCHAR(50) DEFAULT 'Other',
     created_by_admin BOOLEAN DEFAULT FALSE
 );