Consolidate the Install identity schema across lifecycle adapters

[BrettKinny]

This was generated by AI during triage.

Type: HITL

What to build

Choose and implement one authoritative schema contract for the Install identity so Bash install/uninstall and PowerShell install/uninstall cannot drift independently. Preserve the current format-1 compatibility and the rule that state is parsed strictly as data, never sourced or evaluated.

This is deliberately deferred until after v1.1 qualification because changing the cross-language generation/validation seam late in the release would create more migration risk than the regression-locked duplication it replaces.

Acceptance criteria

• Record the chosen schema ownership/generation strategy in an ADR, including why it works in bootstrap environments before optional tooling exists.
• One authoritative field/constraint definition drives or mechanically verifies all four adapter-native readers and writers.
• Format 1 remains readable without executing state content; unknown, missing, duplicate, malformed, unsafe-path, semantic, and case-identity violations still fail closed.
• Bash and PowerShell emit byte-compatible field names and equivalent constraints for stable, prerelease, legacy, edge, adopted-home, and rootless Podman identities.
• Generated artifacts are reproducible from the authoritative schema and CI fails on an ungenerated or hand-diverged adapter.
• Cross-language fixtures cover valid and adversarial state, including CRLF, non-ASCII paths, path case rules, and future-format rejection.
• Migration/versioning rules are documented before adding any format-2 field.

Blocked by

• Qualify the v1.1 Candidate on physical amd64 and arm64 #105