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 existing meme search, browsing, text editor, and keyboard-input entry points. Review how exact-name search and text editing currently work, then define separate checks for category browsing, a clearable search, CAPS input, and shortcuts such as Ctrl+S. Done means each requested interaction works without disrupting meme creation.

Written by the indexing model from the issue text.