Make RFQ quote issuance durable across restarts

[0xMuang]

Scope

• Adds a durable RFQ quote coordinator for persistent nonce/idempotency handling, atomic inventory reservation, signed quote replay, and restart-safe quote lifecycle state.
• Adds fill/cancel observation plus confirmation-depth reconciliation so observed fills/cancels can finalize or roll back on reorg.
• Keeps the bundled Node file-backed store as a single-host reference adapter only; production operators must provide an HA transactional database-backed QuoteCoordinatorStore.
• Updates RFQ service docs, threat model, production RFQ policy, FEATURES, PROGRESS, and QUALITY to mark RFQ-004 as delivered and document remaining production boundaries.

Tests / validation

• npm test --prefix services/rfq — passes locally in this integration step.
• Prior feature validation recorded by implementation lane: forge 857, RFQ E2E, diff, init race.
• git diff --cached --check before commit — clean.
• Secret/scratch scan before commit — no scratch files staged; existing untracked contracts.md, deployments/, and desc.md preserved and not staged.

Known unrelated blocker

• scripts/check.sh is still blocked by pre-existing forge fmt drift in script/DeployProductionCore.s.sol and script/DemoScenarios.s.sol; this PR does not modify those files.

Production boundary

• This PR does not claim the bundled file store is multi-host or HA production storage. Production deployment must wire a transactional DB adapter that enforces the coordinator's unique (chainId, adapter, maker, nonce) and (chainId, adapter, maker, idempotencyKeyHash) constraints atomically.
• No main merge is requested from this branch by automation.

[0xMuang]

Superseded by consolidated delivery PR #89 after the author requested a reduced open-PR surface. This component branch and PR remain available as implementation and review history; no branch was deleted.