Generated documents now download as "YYYY-MM-DD keyword (case number).docx"
(date first/sortable, case number bracketed) instead of the old
"rule-case-date.docx" shape.
- submissionFileName: date-led frame; keyword = user override > lang-aware
rule name > "submission"; case number always bracketed, placeholder
"Az. folgt" (named const) when the project has no Aktenzeichen.
- SanitiseSubmissionFileName hardened to fold the full Windows-reserved
set (colon star question angle pipe) on top of slash/backslash, while
preserving spaces + parentheses so the assembled frame stays
human-facing yet filesystem-safe.
- User-replaceable keyword stored in the draft's composer_meta jsonb
(filename_keyword, no migration). Editor gains a "Stichwort (Dateiname)"
input that placeholders the auto rule name and persists via the draft
PATCH path. One-click /generate has no draft row -> keeps auto keyword.
Tests: submissionFileName (full / no-AZ / override / EN / slash case-no /
blank override / empty rule), submissionFilenameKeyword, extended
sanitiser cases.
t-paliad-354