fix: raise synthesis max_tokens to 64000 and surface truncation explicitly

fix: keep fail-closed per fact but stop zero-verified synthesis from emptying the whole brief

feat: merge Company Overview generation into single synthesis call

feat: multi-provider LLM support, prominent chat, design pass, and new analytics

chore: checkpoint sidebar nav + i18n work-in-progress before Decision Stack redesign

fix: harden _extract_json — use raw_decode to ignore trailing JSON objects and prose

deploy: Primer app for HF Spaces — clean orphan history