Add 60 new playground.* keys and 50 new search.* keys to en.json and
pt-BR.json covering Playground Studio tabs (Chat/Compare/API/Build),
config pane, param sliders, presets, improve prompt, export, compare
metrics (TTFT/TPS), Build tab (tools/structured output), and Search Tools
Studio tabs (Search/Scrape/Compare), SearchConceptCard, ProviderCatalog,
ScrapeResult, and config pane fields.
PT-BR has full Portuguese translations. EN has EN strings.
