[pastewka]

Adds the restart control file and dates the v1.3.0 changelog (27Oct26). Supersedes #33.

Restart control file. As soon as the output NetCDF is set up, every run writes output.restart_control (new key, default restart.json). This is the run's complete control file with two changes:

• initial_density.source is set to this run's output.file, so the continuation starts from the last frame written there;
• output.file is advanced to a new, numbered name: a number at the end of the name (after ., _ or -) is incremented with its zero padding kept, otherwise .1 is appended (design.nc → design.1.nc → design.2.nc, run_009.nc → run_010.nc).

So a continuation never overwrites the file it reads, and repeating mutopopt restart.json chains jobs.

• The file is written at the start rather than the end, so a run killed at the walltime can be continued, from its last dumped frame. The key's help text recommends dump_every > 0 for runs that may be interrupted.
• Keys left at null (automatic) stay null, so the next run makes those choices again.
• Only the design carries over. The optimizer's state (trust-region radius, adaptive tolerance, iteration count) starts fresh.
• The control file the run was started from is replaced only if it is itself a continuation. A hand-written control file of the same name is kept, with a warning.
• Elasticity driver only; simulate_conduction.py is unchanged.

Tests. New test/test_restart_control.py (numbering, contents and validity of the restart file, chaining, the overwrite guard); all of it passes. I also ran the chain twice up to the start of the optimization (design.nc → design.1.nc → design.2.nc). Locally, 8 optimizer tests fail on this branch and on main alike, because the NuMPI in the venv is older than the required >0.15.2.

Release. Requires muGrid 1.6.0 (muSpectre/muGrid#247), so release muGrid first.

🤖 Generated with Claude Code