Lifecycle: extract & display structured contract facts

- New contract_facts table tracks effective_date, term_months, total_value
  (in minor units), currency, auto_renew, notice_days, governing_law per
  document version. Re-uploads/renewals add new rows so changes can be
  charted later.
- New lib/contractFacts.ts: maybeExtractContractFacts() runs an LLM call
  on uploaded text and inserts a row keyed to the doc's current version.
  Fires fire-and-forget alongside counterparty extraction; never blocks.
- GET /projects/:id/facts returns rows sorted newest-first.
- New KeyTermsPanel on the project documents tab (collapsible, default
  open) renders the rows as a compact table with formatted money/term/dates.