Windows Paper-Style Charting Tool

I want to bring the old-school paper charting method into a tidy Windows desktop application. The core of the job is accuracy: every plotted point must respect the exact price scale I give you so that grid spacing, step size, and trend angles match what traders used to draw by hand.

Essential functions
• Plot live or imported price movement as a true line chart on a configurable square grid background.
• Let me add, drag, and edit multiple trend-lines and reference lines while preserving their mathematical relationship to underlying values.
• Offer zoom, pan, and scale controls that never distort those relationships.

The first milestone is a working Windows executable (C#, C++, Python + Qt, or another framework you propose) that:
1. Reads a simple CSV of time-price pairs.
2. Renders the grid-based chart exactly to scale in pixels versus price units.
3. Saves and reloads my manual annotations.

After that we will layer in more chart types and analytics, but the immediate deliverable is the precise, paper-feel line chart described above, with clean, well-commented source code and a short user guide.

If you have experience with high-resolution rendering, coordinate-system math, or financial chart libraries, your insight will be welcome; otherwise just show me that you can keep every plotted value honest to the underlying numbers and we’ll move forward from there.