Schema 1.5.0: holiday calendar registry, citext names; drop num_records

For the coverage-aware holiday-calendar API in TSAPI core (db_base
holiday_calendar__get / __set_coverage / __set_metadata / __upsert).

- meta.holiday_calendars (name, description, covered_from, covered_to,
  source, updated_at): a calendar exists when it has a row here, not
  when it has holidays (retires the 9999-12-31 sentinel row).
  covered_from/to: the range over which the closure list is complete;
  both set or both NULL, from <= to (holiday_calendars_coverage_check).
- Calendar names are citext in every table (registry, holidays.calendar_name,
  exchanges.default_holiday_calendar, instruments.holiday_calendar):
  stored as given, unique and matched case-insensitively -- also in the
  foreign keys -- as the native TSAPI backend does with COLLATE NOCASE.
  New extension citext (00_extensions.sql). Name check: non-empty,
  trimmed, <= 50 characters.
- FKs: holidays -> registry ON DELETE CASCADE; exchanges/instruments ->
  registry ON DELETE RESTRICT (a calendar in use cannot be dropped);
  ON UPDATE CASCADE everywhere.
- meta.series.num_records dropped. Only some write paths maintained it
  (never C++), it sometimes held an estimate, and it was NULL for a series
  never written to. Clients ask the table: count(*), or
  SELECT EXISTS (SELECT 1 FROM <table>) for "is it empty?".
- find_schema_problems() covers the new table, columns, constraints and
  extension, and runs with search_path = pg_catalog so format_type()
  reports 'public.citext' whatever the caller's search_path.

Verified on a fresh database (PG 17): run_setup.py installs it and
find_schema_problems() returns zero rows, also for a caller without
public on the search_path; constraint behaviour checked by hand
(case-insensitive duplicate refused, FK matches any spelling, RESTRICT
and CASCADE, coverage and name checks).

Re-provision databases (no migration).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

sql/09_schema_check.sql

@@ -31,12 +31,17 @@
 -- The schema VERSION string is not compared here: each client compares
 -- meta.schema_version with the version it was built for. This function only
 -- reports a missing version row.
+--
+-- The function runs with search_path = pg_catalog, so format_type() spells
+-- extension types schema-qualified ('public.citext') whatever the caller's
+-- search_path is.
 -- ============================================================================
 
 CREATE OR REPLACE FUNCTION meta.find_schema_problems()
  RETURNS TABLE(object text, problem text)
  LANGUAGE plpgsql
  STABLE
+ SET search_path = pg_catalog, pg_temp
 AS $function$
 BEGIN
     -- Schemas and extension -------------------------------------------------
@@ -48,7 +53,7 @@ BEGIN
 
     RETURN QUERY
     SELECT 'extension ' || e, 'missing'
-    FROM unnest(ARRAY['pg_trgm']) AS e
+    FROM unnest(ARRAY['citext', 'pg_trgm']) AS e
     WHERE NOT EXISTS (SELECT 1 FROM pg_extension WHERE extname = e)
     ORDER BY 1;
 
@@ -92,12 +97,18 @@ BEGIN
         ('meta.exchanges', 'currency', 'character varying(3)', false),
         ('meta.exchanges', 'default_sec_type', 'character varying(18)', false),
         ('meta.exchanges', 'default_session', 'character varying(40)', false),
-        ('meta.exchanges', 'default_holiday_calendar', 'character varying(40)', false),
+        ('meta.exchanges', 'default_holiday_calendar', 'public.citext', false),
         ('meta.exchanges', 'default_tick_size', 'double precision', false),
         ('meta.exchanges', 'default_tick_value', 'double precision', false),
         ('meta.exchanges', 'default_extended_hours', 'boolean', false),
         ('meta.exchanges', 'country', 'character varying(3)', false),
-        ('meta.holidays', 'calendar_name', 'character varying(50)', true),
+        ('meta.holiday_calendars', 'name', 'public.citext', true),
+        ('meta.holiday_calendars', 'description', 'text', false),
+        ('meta.holiday_calendars', 'covered_from', 'date', false),
+        ('meta.holiday_calendars', 'covered_to', 'date', false),
+        ('meta.holiday_calendars', 'source', 'text', false),
+        ('meta.holiday_calendars', 'updated_at', 'timestamp with time zone', true),
+        ('meta.holidays', 'calendar_name', 'public.citext', true),
         ('meta.holidays', 'date', 'date', true),
         ('meta.holidays', 'description', 'character varying(255)', false),
         ('meta.holidays', 'early_close', 'boolean', true),
@@ -111,7 +122,7 @@ BEGIN
         ('meta.instruments', 'strike', 'double precision', false),
         ('meta.instruments', 'currency', 'character varying(3)', false),
         ('meta.instruments', 'session', 'character varying(40)', false),
-        ('meta.instruments', 'holiday_calendar', 'character varying(50)', false),
+        ('meta.instruments', 'holiday_calendar', 'public.citext', false),
         ('meta.instruments', 'sec_id', 'character varying(50)', false),
         ('meta.instruments', 'sec_id_type', 'character varying(20)', false),
         ('meta.instruments', 'description', 'character varying(255)', false),
@@ -150,7 +161,6 @@ BEGIN
         ('meta.series', 'sec_id', 'character varying(30)', false),
         ('meta.series', 'sec_id_type', 'character varying(30)', false),
         ('meta.series', 'create_timestamp', 'timestamp without time zone', false),
-        ('meta.series', 'num_records', 'bigint', false),
         ('meta.series', 'first_timestamp', 'timestamp without time zone', false),
         ('meta.series', 'last_timestamp', 'timestamp without time zone', false),
         ('meta.series', 'bar_type', 'character varying(30)', false),
@@ -218,9 +228,15 @@ BEGIN
         ('log.pending_changes', 'pending_changes_pkey'),
         ('log.event_log', 'event_log_pkey'),
         ('meta.holidays', 'holidays_pkey'),
+        ('meta.holidays', 'holidays_calendar_fkey'),
+        ('meta.holiday_calendars', 'holiday_calendars_pkey'),
+        ('meta.holiday_calendars', 'holiday_calendars_name_check'),
+        ('meta.holiday_calendars', 'holiday_calendars_coverage_check'),
         ('log.script_log', 'script_log_pkey'),
         ('meta.instruments', 'instruments_pkey'),
+        ('meta.instruments', 'instruments_holiday_calendar_fkey'),
         ('meta.exchanges', 'exchanges_pkey'),
+        ('meta.exchanges', 'exchanges_holiday_calendar_fkey'),
         ('meta.sessions', 'sessions_pkey'),
         ('meta.series', 'series_pkey'),
         ('meta.series', 'series_schema_table_key'),