Milestone log

One document per milestone: goal, what was built, design decisions, results, findings (including what did not work) and how to reproduce.

Milestone	Status	Doc	Commit
M0 Environment and project setup	done	M0-setup.md	c8c701a
M1 Baseline and visualizer	done	M1-baseline-visualizer.md	b8e0c0e
M2 Improved greedy solver	done	M2-greedy-solver.md	fe395f6
M3 Preprocessing and importance maps	done (4-image eval)	M3-preprocessing-importance.md	da3f38e
M6 Dataset, evaluation and fabrication output	done	M6-evaluation.md	see git log
M4 Path refinement + parallel solver	done	M4-refinement.md	see git log
M5 Colour string art	done	M5-colour.md	see git log
M7 Interactive demo app	done	M7-demo.md	see git log
M8 Hardening: calibration, exposure, palette, held-out, lint	done	M8-hardening.md	see git log
M9 Build-ready tooling: kit, winding assistant, build guide	done	M9-build-ready.md	see git log
M10 Docs site and online app	done	M10-publishing.md	see git log
Report	done	Project report	see git log

Conventions used in every results table - Images are rendered with the same thread model the solver uses (render.Canvas). - ssim_sK / psnr_sK are computed after blurring both images with a Gaussian of σ = K px, which simulates viewing distance. s0 is the raw render. - Metrics are computed inside the frame mask only. roi variants are restricted to the landmark face oval. - Default setup unless stated: 600 px canvas, circular frame, 256 pins, thread opacity 0.2, min pin gap 10. - Timings were taken on the development laptop (Windows 11, Python 3.12). Wall-clock varies ±2× with background load, so compare timings only within one table.