feat(build): support optional BuildKit secrets

.gitea/actions/quickstack-oci/deploy.test.mjs

@@ -6,6 +6,7 @@ import {
   deployExactImage,
   expandTokens,
   mergeEnvironment,
+  resolveBuildSecretArguments,
   resolveSecretEnvironment,
   orderApplications,
   resolveDeploymentBranch,
@@ -151,6 +152,34 @@ test("version 2 validates promotion contracts and token expansion", () => {
   );
 });
 
+test("passes declared Actions secrets to Docker only through BuildKit secret mounts", () => {
+  const secretValue = "must-not-appear-in-docker-arguments";
+  const artifact = validateArtifact({
+    name: "web",
+    image: "owner/web",
+    buildSecrets: {
+      "next-server-actions-encryption-key": "NEXT_SERVER_ACTIONS_ENCRYPTION_KEY",
+    },
+  });
+  const args = resolveBuildSecretArguments(artifact.buildSecrets, {
+    NEXT_SERVER_ACTIONS_ENCRYPTION_KEY: secretValue,
+  });
+
+  assert.deepEqual(args, [
+    "--secret",
+    "id=next-server-actions-encryption-key,env=NEXT_SERVER_ACTIONS_ENCRYPTION_KEY",
+  ]);
+  assert.doesNotMatch(JSON.stringify(args), new RegExp(secretValue));
+  assert.throws(
+    () => resolveBuildSecretArguments(artifact.buildSecrets, {}),
+    /Missing Actions secret NEXT_SERVER_ACTIONS_ENCRYPTION_KEY/,
+  );
+  assert.throws(
+    () => validateArtifact({ name: "web", image: "owner/web", buildSecrets: { "../invalid": "SECRET" } }),
+    /Invalid BuildKit secret ID/,
+  );
+});
+
 test("application dependencies reject missing nodes and cycles", () => {
   assert.throws(
     () => orderApplications([{ name: "web", dependsOn: ["missing"] }]),