Latvian localization

[EPoikans]

Superset currently does not support Latvian localization and i would like to add support for it.
I am already testing the translation locally and have made localization PRs to dependencies I have spotted from elements not translating from just the superset localization.
python-humanize/humanize#301
dpgaspar/Flask-AppBuilder#2441
apache/echarts#21546

[manimovassagh]

Great initiative -- always good to see more localization coverage. A few things that might help smooth the process:

1. Generate the base .po file if you haven't already:

   cd superset-frontend
   pybabel extract -F babel.cfg -o messages.pot .
   pybabel init -i messages.pot -d translations -l lv

2. Backend translations live in superset/translations/. You'll need to create superset/translations/lv/LC_MESSAGES/messages.po and compile it:

   pybabel compile -d superset/translations

3. Register the locale -- Add lv to LANGUAGES in your superset_config.py:

   LANGUAGES = {
       "en": {"flag": "us", "name": "English"},
       "lv": {"flag": "lv", "name": "Latviešu"},
   }

   Make sure lv is included in the available locales list in the Flask-Babel config.

4. Dependencies -- Good call on the upstream PRs to humanize and Flask-AppBuilder. ECharts translations are trickier since those are bundled separately, but the PR you linked should cover the chart-level strings.

When you're ready to submit the PR to Superset itself, the contribution guidelines ask that you include the .po file (not the compiled .mo). The CI pipeline handles compilation. Looking forward to seeing Latvian support land!