fix(health): add /healthz route and tighten docker healthcheck

app/routes/healthz.tsx

@@ -0,0 +1,8 @@
+// Lightweight unauthenticated health check used by Docker/Caddy.
+// Returns 200 with a tiny JSON body. Do NOT touch the database here:
+// the goal is only to confirm the Node process is serving HTTP.
+export const loader = () =>
+  new Response(JSON.stringify({ ok: true }), {
+    status: 200,
+    headers: { "content-type": "application/json" },
+  });

deploy/docker-compose.dev.yml

@@ -16,7 +16,7 @@ services:
     volumes:
       - /docker/linumiq-invoice/dev/data:/data
     healthcheck:
-      test: ["CMD", "wget", "-qO-", "http://127.0.0.1:3000/healthz", "||", "exit", "0"]
+      test: ["CMD", "wget", "-qO-", "http://127.0.0.1:3000/healthz"]
       interval: 30s
       timeout: 5s
       retries: 3

deploy/docker-compose.prod.yml

@@ -16,7 +16,7 @@ services:
     volumes:
       - /docker/linumiq-invoice/prod/data:/data
     healthcheck:
-      test: ["CMD", "wget", "-qO-", "http://127.0.0.1:3000/healthz", "||", "exit", "0"]
+      test: ["CMD", "wget", "-qO-", "http://127.0.0.1:3000/healthz"]
       interval: 30s
       timeout: 5s
       retries: 3