maintenance: add healthz service

[tschaefer]

No description provided.

[gitguardian]

⚠️ GitGuardian has uncovered 1 secret following the scan of your pull request.

Please consider investigating the findings and remediating the incidents. Failure to do so may lead to compromising the associated services or software components.

🔎 Detected hardcoded secret in your pull request

GitGuardian id	GitGuardian status	Secret	Commit	Filename
23265588	Triggered	Generic High Entropy Secret	43ba2d5	internal/healthz/server_test.go	View secret

🛠 Guidelines to remediate hardcoded secrets

1. Understand the implications of revoking this secret by investigating where it is used in your code.
2. Replace and store your secret safely. Learn here the best practices.
3. Revoke and rotate this secret.
4. If possible, rewrite git history. Rewriting git history is not a trivial act. You might completely break other contributing developers' workflow and you risk accidentally deleting legitimate data.

To avoid such incidents in the future consider

• following these best practices for managing and storing secrets including API keys and other credentials
• install secret detection on pre-commit to catch secret before it leaves your machine and ease remediation.

---

^{🦉 GitGuardian detects secrets in your source code to help developers and security teams secure the modern development process. You are seeing this because you or someone else with access to this repository has authorized GitGuardian to scan your pull request.}

[Copilot]

Pull request overview

Adds a dedicated health check HTTP service (“healthz”) to the Finch manager process, wiring it through the manager runtime, CLI flags, and container startup so operators can probe basic service/DB readiness independently of the main HTTP/Auth ports.

Changes:

• Introduces a new internal/healthz HTTP server with /healthz handler backed by a DB ping/readiness check.
• Refactors Manager.Run to accept an Addresses struct and starts/stops the new healthz server alongside existing servers.
• Adds a new CLI flag and Docker runtime arg for configuring the healthz listen address, plus updates tests accordingly.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
internal/manager/manager_test.go	Updates manager run test to supply a healthz listen address.
internal/manager/manager.go	Refactors Run to take an address bundle and adds healthz server lifecycle management.
internal/healthz/server.go	Implements the new healthz HTTP server and /healthz handler.
internal/healthz/server_test.go	Adds unit tests for healthy/unhealthy/method handling of the healthz handler.
internal/database/database.go	Adds Database.Ping(ctx) used by healthz to validate DB readiness.
cmd/run/run.go	Adds --server.healthz-address flag and passes it into manager startup.
Dockerfile	Supplies the new healthz address flag in the container CMD.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.