chore: migrate CI to Gitea actions and update module path

CHANGELOG.md

@@ -11,7 +11,7 @@ First stable release of nuntius: a small, opinionated, modular contact form
 backend written in Go. A single static binary, four form kinds out of the box,
 SMTP delivery, a JSONL newsletter log, strict TOML configuration, and env-var
 secrets. Its only dependency outside the standard library is the first-party
-[interpres](https://codeberg.org/petrbalvin/interpres) TOML parser.
+[interpres](https://sourcedock.dev/petrbalvin/interpres)
 
 ### Added
 
@@ -49,4 +49,4 @@ secrets. Its only dependency outside the standard library is the first-party
 - **docs/** — `architecture.md`, `configuration.md`, `api-reference.md`,
   `deployment.md`, `security.md`, `library-usage.md`.
 
-[1.0.0]: https://codeberg.org/petrbalvin/nuntius/releases/tag/v1.0.0
+[1.0.0]: https://sourcedock.dev/petrbalvin/nuntius/releases/tag/v1.0.0