DOCS: add Federal Tier 1 jurisdiction wiring PR 1/PR 2 design

Append Section 11 to the path-unification plan specifying the
federal jurisdiction wiring work (previously only referenced in
UPGRADE_PRIORITIZATION.md, never specified).

- 8 federal Tier 1 entries with law_ids, domains, saski_bucket
- Q1-Q4 consensus decisions (verbatim, June 22 2026 round)
- Two-resolver mapping: posture (jurisdiction_resolver.py) vs
  statute scope (jurisdiction_scope.py)
- Jurisdiction-stack change: effective_statute_jurisdictions
  emits [state_code, "US"] instead of a single code
- federal_* module list + run_federal_statute_checks dispatcher
- HIPAA mode/domain-gated PII overlay in ComplianceMatrix (PR 2)
- FEDERAL_STATUTE_TRUST_BOUNDARY invariant + test requirements
- COPPA / ADA-TITLE-I left unwired (capability metadata only)
- US-CSAM-REPORTING evidence-only handling

Planning artifact only. Authorizes no code changes.

Co-authored-by: Cursor <cursoragent@cursor.com>
