Schema 1.4.0: drop meta.sessions.json

The definition string is the only stored schedule. The "json" column held a
parsed copy that the Python client wrote, the C++ client never wrote, and
neither client read -- and a raw UPDATE of one field silently left two
different schedules. Clients derive the parsed form from the definition.
09_schema_check.sql no longer expects the column; VERSION and
10_schema_version.sql at 1.4.0. Re-provision databases (no migrations).

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

sql/10_schema_version.sql

@@ -5,4 +5,4 @@
 -- they were built for (Python: DB_SCHEMA_VERSION in tsapi_pgdb/_version.py).
 
 INSERT INTO meta.schema_version (version, description)
-VALUES ('1.3.0', 'meta.find_series_registry_mismatches()');
+VALUES ('1.4.0', 'meta.sessions.json dropped: the definition is the only schedule');