Explore guided checkerboard calibration workflow

[gsrunion]

Proposal:

• Add a guided checkerboard capture mode to help operators gather calibration images with better coverage.

Guidance goals:

• center / corners / edges of frame
• distance variation
• tilt variation
• "good enough" operator feedback, not precision alignment

Why:

• Calibration quality depends more on diverse coverage than random captures
• A guided flow should reduce bad or repetitive datasets

Prototype/reference code:

• openscan-pipeline/src/calibrate_guided.py

Note:

• Current prototype is only a reference for workflow shape, not final UX.