Talk about posture, stretches, eye strain

This is something I feel is somewhat overlooked but can lead to pretty deleterious effects if not incorporated into daily life. I propose adding a section (maybe after the finger exercises) about some stretches you can do while sitting, when and how often to take breaks, resting/recovering eye muscles, maybe even general diet tips and links to explanation of spinal health habits (thinking something like The Alexander Technique).

Read the existing guide around the finger exercises and assess where a health-and-breaks section would fit. Define a focused scope from the proposed stretches, break timing, eye strain, diet tips, and spinal-health links, then confirm reliable sources. Done means the guide contains an agreed, useful section with links and clear advice.

Written by the indexing model from the issue text.