FIX[BE]: fix logic on Chickin Laying not convert to layer but still Pullet, and inisiate laying transfer migration and base basic API

internal/database/migrations/20251029074825_create_laying_transfers_table.up.sql

@@ -1,14 +1,15 @@
 CREATE TABLE IF NOT EXISTS laying_transfers (
     id BIGSERIAL PRIMARY KEY,
+    transfer_number VARCHAR(50) UNIQUE NOT NULL,
     from_project_flock_id BIGINT NOT NULL,
     to_project_flock_id BIGINT NOT NULL,
     transfer_date DATE NOT NULL,
-    total_qty INTEGER,
+    total_qty NUMERIC(15, 3) NOT NULL,
     notes TEXT,
     created_at TIMESTAMPTZ DEFAULT now(),
     updated_at TIMESTAMPTZ DEFAULT now(),
     deleted_at TIMESTAMPTZ,
-    created_by BIGINT
+    created_by BIGINT NOT NULL
 );
 
 -- FOREIGN KEYS (dijalankan setelah semua tabel parent ada)
@@ -37,6 +38,10 @@ BEGIN
 END $$;
 
 -- INDEXES
+CREATE UNIQUE INDEX IF NOT EXISTS idx_laying_transfers_transfer_number ON laying_transfers (transfer_number)
+WHERE
+    deleted_at IS NULL;
+
 CREATE INDEX IF NOT EXISTS idx_laying_transfers_from_project_flock_id ON laying_transfers (from_project_flock_id);
 
 CREATE INDEX IF NOT EXISTS idx_laying_transfers_to_project_flock_id ON laying_transfers (to_project_flock_id);