chore: expose deployment identity in health

frontend/src/app/api/health/route.ts

@@ -7,6 +7,11 @@ type Check = {
 };
 
 const jyotishApiBase = process.env.JYOTISH_API_BASE ?? "http://127.0.0.1:5200";
+const gitCommit =
+  process.env.GITHUB_SHA
+  ?? process.env.VERCEL_GIT_COMMIT_SHA
+  ?? process.env.NEXT_PUBLIC_GIT_COMMIT
+  ?? "unknown";
 
 function envCheck(names: string[]): Check {
   const missing = names.filter((name) => !process.env[name]);
@@ -65,6 +70,9 @@ export async function GET() {
     {
       status,
       timestamp: new Date().toISOString(),
+      deployment: {
+        gitCommit,
+      },
       checks,
     },
     { status: status === "ok" ? 200 : 503 },

frontend/tests/health-deployment.test.ts

@@ -0,0 +1,12 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import test from "node:test";
+
+test("health endpoint exposes deployment identity for production verification", () => {
+  const source = readFileSync(new URL("../src/app/api/health/route.ts", import.meta.url), "utf8");
+
+  assert.match(source, /deployment:/);
+  assert.match(source, /GITHUB_SHA/);
+  assert.match(source, /VERCEL_GIT_COMMIT_SHA/);
+  assert.match(source, /gitCommit/);
+});