Changes:
- Filter bar: old industry filters (🚗, 💊, etc.) replaced with service categories: All, Consult, Website Development
- Card categories updated per user spec:
- Dataroot → consult only
- เลือดจระเข้วานิไทย → both consult + webdev (multi-category)
- All other 7 cards → webdev
- Filter JS updated: reads data-category (comma-sep) instead of industry text
- Multi-category via comma-separated values in data-category attribute
- Portfolio page: home + portfolio page both reflect new categories
- Added gradient transitions between sections in global.css
- Portfolio section now has gradient-top (dark to white fade)
- Blog section now has gradient-bottom (white fade from dark)
- Reduced portfolio overlay opacity from 0.85 to 0.65
- Added border to blog cards for white-on-white visibility
- Blog cards now have primary color accent on hover
