docs: build out CoreLink v1 developer documentation

[jaavid]

Summary

Build out the versioned v1 developer-doc tree on top of the now-merged contract-backed quickstart.

Added

• architecture and provider-boundary concepts
• authentication/tenant-context guidance
• Device/Command guide for the current public draft
• maturity-aware telemetry/location/events and partner/webhook guides
• TypeScript/Python SDK guidance without freezing invented wrapper APIs
• Java/CLI/mock/MCP maturity/status guidance
• errors/retries/idempotency and troubleshooting operations docs
• compatibility and maturity references
• complete v1/root navigation

Safety and maturity

• no new public endpoints are invented
• telemetry/partner/tool pages remain explicitly contract/release-gated
• mock-server guidance corrects the stale claim that OpenAPI/AsyncAPI are empty
• browser token guidance uses server-side session/BFF patterns where appropriate
• draft/scaffold content is never promoted to Stable

This clean PR supersedes conflicted PR #10, which had been stacked on the pre-squash quickstart branch.