Add coverage-universe targets for uninsured and private coverage

Context

The healthcare tab currently focuses on ACA, Medicaid/CHIP, and Medicare program targets. It does not yet include the broader health coverage universe that explains what people have when they are not in those programs.

Missing coverage-universe targets include uninsured, employer-sponsored insurance, direct-purchase/private coverage, and related mutually-exclusive or overlapping coverage categories.

Goal

Add coverage-universe targets/diagnostics so healthcare release comparisons can distinguish program-specific misses from overall health insurance coverage composition misses.

Suggested implementation

• Inventory available source support, likely from CPS/ACS/Census or other health insurance coverage tables already flowing through Ledger/Populace.
• Decide whether targets should be person-level annual coverage, interview/current coverage, or both, matching PolicyEngine-US variable semantics.
• Add target roles for feasible concepts, such as:
  • uninsured
  • employer-sponsored insurance
  • direct-purchase/private coverage
  • Marketplace vs non-Marketplace direct purchase where source support allows
• Add diagnostics for category overlap/mutual-exclusivity so totals are interpretable.

Acceptance criteria

• Release artifacts expose coverage-universe target availability and source semantics.
• Tests cover mapping to the intended PolicyEngine-US variables or explicitly document formula/source ownership boundaries.
• Healthcare diagnostics can show whether program-target errors are accompanied by broad coverage-composition errors.
• Missing categories are recorded as unavailable or deferred rather than silently absent.

Start by inventorying the health coverage sources already flowing through Ledger/Populace and the relevant PolicyEngine-US variable semantics. Define which person-level or current-coverage concepts are supported, then trace how release artifacts and healthcare diagnostics expose targets. Done means feasible categories, overlap rules, source ownership, and deferred categories are covered by tests or explicitly documented.