Release v0.3.1

[github-actions]

Release v0.3.1

Auto-generated by the Prepare Release workflow.

What changed

• electron/package.json (+ lockfile) bumped to 0.3.1 — this is the
  version electron-builder/electron-updater use, and release.yml refuses
  to build a tag that doesn't match it
• Pre-flight checks passed: uv lock --check, git deps pinned to SHAs/tags

Review checklist

• Version is correct in electron/package.json
• CI passes

Manual checks the automated suite cannot cover

Do these on a real machine — CI has no GPU/display and the migrated
suite forces SPYDE_NO_DASK=1:

• Distributed navigator path — open a multi-GB 4D-STEM scan, drag the
  navigator; the diffraction pattern must track without freezing. If the
  repro_*.py distributed scripts are present, run them directly
  (uv run python -m spyde.tests.repro_<name>); they spin a real
  LocalCluster and won't run under pytest.
• GPU find-vectors / orientation — on a CUDA box, run Find Vectors and
  Orientation Mapping on a real dataset (e.g. pyxem.data.sped_ag()); confirm
  results look right and nothing segfaults. (The numba subpixel kernel is unit-
  tested for arithmetic, but the live CUDA path needs a real run.)
• No-GPU fallback — on a machine without numba/CUDA, the app must still
  launch and Find Vectors must fall back to CPU. (Guarded by
  test_find_vectors_no_numba.py, but verify the PACKAGED app.)
• IPF colour-key legend — open an Orientation map; the colour-key triangle
  pins in the corner on the 2-D map and hides on the 3-D view.
• Clean shutdown — quit the app; confirm no orphaned python.exe / Dask
  worker processes remain (Task Manager / ps).

After merging

Tag the merge commit on main — the tag MUST be exactly v0.3.1:

git fetch origin
git tag v0.3.1 origin/main
git push origin v0.3.1

The tag push triggers release.yml (3-platform build → draft release →
publish once all legs pass).

• Confirm the release actually has installers before announcing it:
  gh release view v0.3.1 --repo CSSFrancis/spyde --json assets --jq '.assets[].name'
  — expect the three installers (SpyDE Setup *.exe, SpyDE-*.dmg,
  SpyDE-*.AppImage), their .blockmaps, and the latest*.yml update
  feeds. release.yml's finalize job refuses to un-draft an
  asset-less release, but check.