Add Brazilian court docket search via DataJud CNJ (v0.4.0)

Adds br_search_processos and br_get_processo, wrapping CNJ's public
DataJud API (shared key openly published by CNJ) across 91 courts.

Scope stated honestly: this covers docket/procedural metadata (classe,
orgao julgador, movimentos), not ruling/acordao/ementa full text - that
remains an open gap (STF portal is WAF-blocked, LexML 404s, no confirmed
full-text HuggingFace dataset beyond a single state court). STF itself
has no DataJud index by design (confirmed 404, not an outage).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>