Add categories and better text tools

Finding memes is a pain. Have to scroll forever or guess the exact name.

**Current issues:**
- Can only search by exact name
- No way to browse by type
- Text editor is too basic
- No keyboard shortcuts

**What would help:**
- Category buttons (Funny, Reaction, etc.)
- Better search with clear button
- CAPS button for text
- Keyboard shortcuts like Ctrl+S

Would make creating memes so much faster and easier.

Start by locating the meme search, category browsing, and text editor UI described in the issue. Review how search input, text editing, and keyboard events are currently handled. Done means users can browse categories, clear searches, toggle CAPS, and use shortcuts such as Ctrl+S without disrupting meme creation.

Written by the indexing model from the issue text.