v2.4.0

Lazy settings via pydantic-settings, JSONB params filtering for task
history, and customisable route prefixes.

• Settings are now lazy — resolved on first access instead of at import
  time. Env vars use a FLUID_ prefix by default; legacy unprefixed names
  are kept as aliases.
  (#100)
• The task database plugin accepts a route_prefix parameter for
  customising history route URLs and replaces with_task_history_router()
  with a register_routes() method.
  (#100)
• Task history queries support filtering by run params via a new params
  field (renamed from HistoryQuery to TaskHistoryQuery).
  (#99)
• Database migration required: the params column is now JSONB with
  a GIN index. See the example
  migration
  for the schema changes.
• Removed get_logger from fluid.utils.log. Task loggers are now obtained
  directly via logging.getLogger(module).