Install SG15 as a family that recommends no cutoffs

[elinsc-bot]

Closes #135. Depends on #127.

Problem

koopmans installed SG15 as a family whose class carries recommended cutoffs, keyed by stringency. SG15 publishes none, so the family defined none, and asking it for them raised:

ValueError: failed to obtain recommended cutoffs for pseudo family
            `CutoffsPseudoPotentialFamily<SG15/1.2/PBE/SR>`: no default
            stringency has been defined.

The class asserted a capability the archive can never fill. Reproduced against main with a synthetic archive: a fresh install of either the scalar- or fully-relativistic variant comes out with no stringency at all.

Changes

• Install SG15 as a plain PseudoPotentialFamily — what SG15 is, and what aiida-pseudo install family produces by default. The cutoffs come from the input file.

Testing

• The installer runs for real against a synthetic archive served through a patched urlopen, with the pinned checksum swapped for that archive's own, so no test reaches the network. The archive carries 1.0 and fully relativistic members too, so the version and variant selection is tested rather than assumed.
• Reverting the installer fails the class assertion. The selection test passes either way — it pins the regex, it does not evidence this change.
• Depends on Take the cutoffs from the input when the pseudo family has none #127, which brings both halves this needs: the ecutrho = 4 x ecutwfc derivation, and the aiida-quantumespresso patched clone that lets a family recommending no cutoffs build at all.

[read-the-docs-community]

Documentation build overview

📚 koopmans-dev | 🛠️ Build #33963510 | 📁 Comparing 7ce1a05 against latest (e296e00)

  🔍 Preview build  

3 files changed

± input_schema.html
± _modules/koopmans/input_file.html
± _modules/koopmans/input_file/pw.html

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.87%. Comparing base (bbda444) to head (7ce1a05).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #136      +/-   ##
==========================================
+ Coverage   81.81%   81.87%   +0.05%     
==========================================
  Files          44       44              
  Lines        3464     3464              
  Branches      543      543              
==========================================
+ Hits         2834     2836       +2     
+ Misses        494      493       -1     
+ Partials      136      135       -1     

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