feat: add verified read-only M0 research ingress

[Pigbibi]

Summary

• add a closed, token-authenticated M0 research ledger ingress and authenticated dashboard read endpoint
• bind accepted ledgers to fixed QAR/QRS provenance, canonical ledger digest, archive-first KV storage, bounded size, and a 14-day physical TTL
• project seven-day research freshness into a distinct dashboard schema without mutating the immutable stored ledger
• add real QAR snapshot shape to QRS publisher canonical JSON to Worker cross-contract coverage

Safety

• dedicated M0 token only; no fallback to control, execution, adaptive, or research-task tokens
• invalid or replayed input cannot overwrite the valid current ledger
• replay/rollback protection is explicitly best-effort because Workers KV is eventually consistent
• no selector, strategy, platform, runtime, dispatch, broker, order, weight, or UI-action path is added

Validation

• node tests/strategy_switch_worker_validation.mjs passed locally
• python -m unittest tests.test_m0_research_ledger tests.test_build_m0_research_publisher_envelope passed locally: 16 tests
• independent Sol audit passed the real QAR to publisher to Worker path
• GitHub CI will run repository checks