Canonical TSAPI series DB schema v1.0.0

Single source of truth for the timeseries PostgreSQL schema shared by the
Python (TSAPI_SERIESDB_PG_PY) and C++ (TSAPI_POSTGRES_CPP) libraries. SQL
seeded byte-for-byte from TSAPI_SERIESDB_PG_PY/tsapi_pgdb/sql on 2026-09-02.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

sql/migrate/migrate_drop_series_if_exists.sql

@@ -0,0 +1,48 @@
+-- Migration: repair meta.drop_series_if_exists()
+--
+-- The function dropped a registered series without setting
+-- application.dropping_series, so the prevent_direct_drop event trigger
+-- rejected its own DROP:
+--
+--   Table series.X is registered in series and can only be dropped
+--   using TimeseriesDB.drop_series()
+--
+-- Unlike meta.drop_series() and meta.drop_all_series(), which set the flag
+-- correctly, this one never did -- so it always failed on exactly the case it
+-- exists to handle. The Python API does not call it, which is why the defect
+-- went unnoticed.
+--
+-- New databases pick this up from 05_procedures.sql. Run this against any
+-- database initialised before the fix.
+--
+-- Safe to run more than once (CREATE OR REPLACE).
+
+CREATE OR REPLACE FUNCTION meta.drop_series_if_exists(_table_name text, _schema_name text DEFAULT 'series'::text)
+ RETURNS void
+ LANGUAGE plpgsql
+AS $function$
+BEGIN
+    -- Check if the series exists in series table
+    IF EXISTS (
+        SELECT 1 FROM meta.series
+        WHERE "table_name" = _table_name
+        AND "db_schema" = _schema_name
+    ) THEN
+        -- Signal the prevent_direct_drop event trigger that this DROP is
+        -- coming from a sanctioned procedure. Without it the trigger rejects
+        -- the statement below, because the table is registered in meta.series.
+        -- Local to the transaction, so it cannot leak to later statements.
+        PERFORM set_config('application.dropping_series', 'true', true);
+
+        -- Drop the table
+        EXECUTE format('DROP TABLE IF EXISTS %I.%I', _schema_name, _table_name);
+
+        -- Remove from series table
+        DELETE FROM meta.series
+        WHERE "table_name" = _table_name
+        AND "db_schema" = _schema_name;
+
+        PERFORM set_config('application.dropping_series', 'false', true);
+    END IF;
+END;
+$function$;