Publish the CoreLink v1 30-minute quickstart

[jaavid]

Related: #3

What changed

• publishes a contract-backed 30-minute v1 quickstart for bearer auth, tenant scoping, Device and Command calls
• documents the current credential boundary without inventing a token-issuance endpoint
• covers idempotent command submission, standard problem responses, safe retries and tenant-isolation verification
• links the quickstart from the versioned docs indexes
• extends Documentation CI with contract markers from the quickstart

Contract boundary

Targets the current 1.0.0-draft public Device + Command slice. TypeScript/Python remain prerelease Alpha; no Stable SDK or production endpoint is claimed.

Validation

Local equivalent of Documentation CI passed:

• versioned docs and quickstart files present
• 1.0.0-draft and corelink_device_id retained
• Bearer auth, tenant-scoped Device path and Idempotency-Key markers verified

GitHub Actions evidence is intentionally pending while the current GitHub Actions incident is active.