Wires the v3 Gericht/System multi-select filter on the Pathway B/B2
panel. 10 forum-bucket chips per m's spec lock §10 Q8 (UPC CFI, UPC
CoA, DE LG/OLG/BGH/BPatG, EPA Erteilung/Einspruchsabt./Beschwerdek.,
DPMA).
UX:
- Chip click toggles its membership in activeForums Set.
- Multi-select; chips AND across the result set
(UNION within forum, AND with other filters — backend handles).
- ?forum=<comma-separated> URL state round-trips on every toggle.
- popstate restores active set; lang switch re-renders chip labels.
- Shared between B1 and B2: tree-mode reissues runB1Search;
filter-mode dispatches input event on the search box.
Frontend file deltas:
- frontend/src/client/fristenrechner.ts: FORUM_BUCKETS array,
activeForums Set, renderForumChips(), reissueSearchWithCurrentFilters()
(mode-aware), getActiveForumsParam() consumed at every search call.
- B2 search fetch + B1 cascade fetch both send ?forum= when active.
Frontend i18n keys for the 10 forum labels (DE+EN) shipped with
Phase B; this commit just renders them.
Backend was wired in Phase C; this commit completes the user-facing
path. Forum filter narrowing applies AND-wise with q / event_category_slug
/ proc / party / source — empty-result UX shows the existing "no hits"
status, m can drop a chip to widen.
Build: clean. Frontend bundle unchanged size delta (≈+50 lines, 1473 keys).
Phase D-2 (party-perspective selector + is_bilateral mirroring renderer)
ships next.
c399caff75