feat(spec): establish Spec 0.2 design baseline

[qwerfunch]

Summary

Establishes the accepted Spec 0.2 target-design baseline for Cladding 0.10.0 as a bounded continuation router plus canonical decision owners. Adds executable design-ledger validation, deterministic simulations, MCP claim-state separation, token accounting, and the three completed design-validation feature records.

The shipped runtime remains schema 0.1. D01-D23 remain explicitly implementation pending and will land through separate F1-F9 feature branches.

Verification

• npm test — 2,992/2,992
• npm run typecheck
• npm run lint
• npm run stage:drift — zero error-severity findings
• npm run conformance — 33/33, L4
• node bin/clad check — 15-stage gate GREEN on the clean commit
• npm run validate:spec-0.2

Scope

• Minor — accepted target design and additive contributor validation surface
• No Spec 0.2 runtime cutover
• No Ironclad upstream fork
• No weakening of the shipped 0.1 gate

Reviewer notes

This PR intentionally separates accepted design from shipped behavior. Pending runtime journeys, reference-host E2E, MCP adoption, and live-host token advantage remain labelled implementation_pending, not_run, or inconclusive rather than being promoted to PASS.

A delegated pre-merge review also identified possible follow-up hardening around discriminating MCP/model fixtures, canonical-owner attestation coverage, README test-file counts, and the repository CHANGELOG contract. Those findings are not hidden by this baseline PR and can be resolved during review before merge if required.