Remove mock runtime functionality and config toggles

Add Postgres persistence backend and shared repositories

Refactor Mongo persistence into modular backend package

Add typed LLM config and modularize constants

Fix DBRef link queries and harden cascade deletes

Refactor tracing into dedicated package and update imports

Remove automatic third-party tracing instrumentation

Add dynamic model linking for custom schemas

Remove core starred session support

Refactor Mongo lifecycle and client_id message contracts

Clean up outdated trace_context doc example

Make runner run() non-streaming and move TODOs to README

Add AGENTS instructions and update runner TODO note

Add .codex to .gitignore and note unused on_stream_event callback

Replace api_type with provider_options for flexible LLM configuration