Fix: FilterSelect implicit validation breaks form on hidden column (#1281)

[radimvaculik]

Summary

Fixes #1281.

Nette\Forms\Controls\SelectBox constructor adds an implicit Filled validation rule when no prompt is set. For a FilterSelect on a column that's hidden via setDefaultHide() or handleHideColumn, the input isn't rendered, so nothing is submitted for it. The rule then fails, the filter container becomes invalid, and Container::getValues() in Datagrid::filterSucceeded() triggers:

Nette\Forms\Container::getValues() invoked but the form is not valid (form 'filter').

Filters are search inputs, not required data entry, so this PR resets the rules on the underlying SelectBox in FilterSelect::addControl(). The fix is inherited by FilterMultiSelect (no-op there since addMultiSelect doesn't add implicit validation).

Test plan

• Added regression test testFilterSelectHasNoImplicitValidation in tests/Cases/FilterTest.phpt — verified it fails before the fix and passes after.
• make tests — 29 passed, 1 skipped (MySQL not running).
• make phpstan — clean.
• make cs — clean.

@jaroslavlibal could you give this branch a try in your project and confirm the warning is gone? 🙏

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 47.54%. Comparing base (e5faff0) to head (894e9d0).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1282      +/-   ##
==========================================
+ Coverage   46.79%   47.54%   +0.75%     
==========================================
  Files          53       53              
  Lines        2729     2730       +1     
==========================================
+ Hits         1277     1298      +21     
+ Misses       1452     1432      -20     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[jaroslavlibal]

I can confirm that the fix works in my project. Thank you!