fix(lang): update Russian localization and remove dead keys across all locales

[iospro]

Summary

• Complete overhaul of Russian localization (lang/main-ru.json): 100% key coverage (1500/1500), unified terminology, fixed translation quality issues
• Removed dead i18n keys (localRecording.labelToolTip, transcribing.labelToolTip, toolbar.accessibilityLabel.collapse) from main.json and all 59 language files

Dead key removal across all 60 lang files

localRecording.labelToolTip, transcribing.labelToolTip and toolbar.accessibilityLabel.collapse are not referenced anywhere in the source code (.ts/.tsx). Removed from main.json and all 59 locale files.

The only retained labelToolTip key is e2ee.labelToolTip, which is actively used in E2EELabel.tsx.

Changes

File	Details
main-ru.json	+462 lines: 166 new translations, quality fixes, terminology unification
main.json	Removed 3 dead keys
59 × main-*.json	Removed dead keys localRecording.labelToolTip, transcribing.labelToolTip, toolbar.accessibilityLabel.collapse

[jitsi-jenkins]

Hi, thanks for your contribution!
If you haven't already done so, could you please make sure you sign our CLA (https://jitsi.org/icla for individuals and https://jitsi.org/ccla for corporations)? We would unfortunately be unable to merge your patch unless we have that piece :(.