Add explicit Forgejo deployment structure with artifact build pipeline

- Introduce clear directory separation for docker, infra, ci, and config
- Add CloudFormation pipeline for S3 → CodeBuild → ECR
- Implement explicit artifact build script for flat deployment zip
- Provide example runtime configuration and ignore secrets

scripts/build-artifact.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+ARTIFACT_DIR="${ROOT_DIR}/artifacts"
+ZIP_PATH="${ARTIFACT_DIR}/forgejo-source.zip"
+
+mkdir -p "${ARTIFACT_DIR}"
+
+tmpdir="$(mktemp -d)"
+trap 'rm -rf "${tmpdir}"' EXIT
+
+cp "${ROOT_DIR}/docker/Dockerfile"        "${tmpdir}/Dockerfile"
+cp "${ROOT_DIR}/docker/entrypoint.sh"     "${tmpdir}/entrypoint.sh"
+cp "${ROOT_DIR}/config/app.ini"            "${tmpdir}/app.ini"
+cp "${ROOT_DIR}/ci/buildspec.yml"          "${tmpdir}/buildspec.yml"
+
+(
+  cd "${tmpdir}"
+  zip -r "${ZIP_PATH}" .
+)
+
+echo "Artifact created: ${ZIP_PATH}"