fix repeatable migrations

db/routines/R__029_fn_negative_price_predictions.sql

@@ -0,0 +1,59 @@
+create or replace function ems.fn_negative_price_predictions(p_site_id int)
+returns jsonb
+language sql
+stable
+as $fn$
+  with hist as (
+    select count(distinct (mip.interval_start at time zone 'Europe/Prague')::date)::int as ndays
+    from ems.market_interval_price mip
+    where mip.market_source in ('OTE_CZ', 'OTE_CZ_DAM')
+      and mip.interval_start >= now() - interval '400 days'
+  ),
+  rows as (
+    select
+      p.predicted_date,
+      p.window_start_hour,
+      p.window_end_hour,
+      p.probability_pct,
+      p.expected_min_price,
+      p.reason
+    from ems.predicted_negative_price_window p
+    where p.site_id = p_site_id
+      and p.predicted_date > (
+        current_timestamp at time zone coalesce(
+          nullif(trim((select s.timezone from ems.site s where s.id = p_site_id)), ''),
+          'Europe/Prague'
+        )
+      )::date
+      and p.predicted_date <= (
+        current_timestamp at time zone coalesce(
+          nullif(trim((select s.timezone from ems.site s where s.id = p_site_id)), ''),
+          'Europe/Prague'
+        )
+      )::date + 7
+    order by p.predicted_date, p.window_start_hour
+  )
+  select jsonb_build_object(
+    'predictions',
+    coalesce(
+      (
+        select jsonb_agg(
+          jsonb_build_object(
+            'predicted_date', r.predicted_date,
+            'window_start_hour', r.window_start_hour,
+            'window_end_hour', r.window_end_hour,
+            'probability_pct', r.probability_pct,
+            'expected_min_price', r.expected_min_price,
+            'reason', coalesce(r.reason, '')
+          )
+        )
+        from rows r
+      ),
+      '[]'::jsonb
+    ),
+    'insufficient_history', (select ndays < 28 from hist)
+  );
+$fn$;
+
+comment on function ems.fn_negative_price_predictions(int) is
+  'Predikovaná okna záporných cen + flag nedostatečné historie OTE.';