Add English translations for remaining Help texts

[lukisch]

Description

BACH has 187+ help topics in system/docs/help/*.txt. Most are in German.
The translation infrastructure exists (t() function, languages_translations table).

Task

Pick 5-10 help files and add English translations to languages_translations using:

bach lang scan --namespace help

Getting Started

1. bach help list -- see all help topics
2. Pick untranslated ones (check bach lang status)
3. Add translations via bach lang add <key> <namespace> en "<translation>"

Difficulty

Beginner -- requires basic German reading + English writing. No code changes needed.