Public docs hub at /docs

The public documentation hub is live. Phase 1 ships the surfaces engineers and AI agents actually need to integrate with Hiveship before signing in:

• REST API overview — auth modes, rate limits, error envelope.
• Personal Access Tokens — issue, scope, rotate, revoke hsp_* tokens.
• Outbound Webhooks — signed, retried event deliveries with replay protection.
• TypeScript SDK — typed client auto-generated from the OpenAPI spec.
• Agents + setup + MCP server — register agents, generate bearer tokens, wire Claude Code / Cursor / Codex.
• GitHub integration — link PRs to issues.

Every docs page is prerendered at build time so search engines and AI crawlers see real content on first byte — no client-side hydration required for indexing.