Revert "Merge: t-paliad-133 — Fristenrechner v3 (Pathway A/B fork + B1 decision tree + B2 forum filter + retire legacy tabs)"

This reverts commit f7d72ff1d3, reversing
changes made to 1ea983f0c7.

internal/db/migrations/050_bilateral_rules_backfill.down.sql

@@ -1,9 +0,0 @@
--- t-paliad-133 Phase A bilateral-tag rollback.
-UPDATE paliad.deadline_rules
-   SET is_bilateral = false
- WHERE code IN (
-        'de_null.stellungnahme',
-        'epa_opp.r79_further',
-        'epa_opp.r116',
-        'epa_app.r116'
-       );