Fix: Add pandas to notebooks dependencies

[harikapadia999]

Description

Fixes #151 - Resolves ModuleNotFoundError: No module named 'pandas' when running sam3_image_predictor_example.ipynb

Problem

The example notebook sam3_image_predictor_example.ipynb requires pandas but it was only listed in the dev optional dependencies, not in notebooks dependencies. Users installing with pip install -e ".[notebooks]" would encounter an import error.

Solution

Added pandas to the notebooks optional dependencies in pyproject.toml

Testing

• Verified pandas is now included in notebooks dependencies
• Change is minimal and non-breaking
• Aligns with existing dev dependencies that already include pandas

Checklist

• [x] Fixes reported issue #151
• [x] Minimal change (single line addition)
• [x] No breaking changes
• [x] Follows existing dependency structure