Add Page Rotation Controls in PDF Viewer

📝 Description:
When a PDF page is formatted vertically (portrait) but contains wide tables, diagrams, or long rows, it’s hard to read without rotating the entire document externally. Provide in‑viewer buttons to rotate the current page 90° left or right—so users can quickly switch to a landscape view for better readability. 🔄📑

✨ What new feature or change would you like to see added in RemNote?
A simple rotate control (e.g., 🔃 icons) in the PDF toolbar that rotates the active page 90° clockwise or counterclockwise.

🤔 What problem does it solve for you? How would it improve your workflow or experience with RemNote?
It removes the need to export or re-save the PDF just to view a single page sideways, saving time and keeping me focused in one app. This makes reading wide content—like spreadsheets or panoramic diagrams—smooth and uninterrupted.

💡 Additional Benefits:

• 🕹️ Instant orientation adjustment without external tools

• 👓 Enhanced clarity on detailed visuals and tables

• 📚 Streamlined study flow when reviewing diverse PDF layouts

• 🚀 Maintains context by rotating only the view, not the file itself