The "production-grade platform" release. Eighteen feature commits fill
in every box a serious infra-tool review checks: middleware hygiene,
observability, declarative validation, machine-readable docs, performance
numbers, deployment hardening, schema migrations, retry-safe webhook
delivery, compliance export, Kubernetes probes, and a rebuilt CLI.

Highlights:
  - Idempotency-Key on every mutating POST + precise rate-limit headers
  - Structured JSON logging + in-process Prometheus metrics + /status page
  - /livez + /readyz Kubernetes-grade probe split
  - @validate_body decorator + auto-generated OpenAPI 3.1 + Swagger UI
  - Streaming /v1/audit/export with chain-verification manifest
  - haldir_migrate: forward-only, checksum-verified schema migrations
  - Webhook delivery with retries, event IDs, deliveries log endpoint
  - /v1/admin/overview single-call tenant dashboard
  - SQLite pragma tuning: -52% on session-lookup p99
  - Multi-stage non-root Dockerfile + CycloneDX SBOM
  - CLI: haldir overview/status/ready/audit export/audit verify/
         webhooks deliveries/migrate
  - In-browser /demo playground at haldir.xyz

Test suite: 79 → 310. mypy strict: 9 → 18 files. Zero new runtime deps.

Full changelog: https://github.com/ExposureGuard/haldir/blob/main/CHANGELOG.md