* feat(reflect): make source facts in search_observations configurable
The recent fix (#669) hardcoded include_source_facts=False in
search_observations to prevent context overflow. This makes it
configurable via HINDSIGHT_API_REFLECT_SOURCE_FACTS_MAX_TOKENS
(env/tenant/bank), defaulting to -1 (disabled).
- -1: source facts disabled (current behavior, default)
- 0: source facts enabled with no token limit
- >0: source facts enabled with a token budget
* docs: add reflect_source_facts_max_tokens to configuration reference
* fix: update configurable fields count in tests and regenerate docs skill
