feat: add acknowledged_by and acknowledged_date columns to violations schema

db/schema.sql

@@ -23,6 +23,8 @@ CREATE TABLE IF NOT EXISTS violations (
     negated_at           DATETIME,
     prior_active_points  INTEGER, -- snapshot at time of logging
     prior_tier_label     TEXT,    -- optional human-readable tier
+    acknowledged_by      TEXT,    -- employee name who acknowledged receipt
+    acknowledged_date    TEXT,    -- date of acknowledgment (YYYY-MM-DD)
     created_at           DATETIME DEFAULT CURRENT_TIMESTAMP
 );