fix(infra): 9router Caddy timeouts — false 504 on slow LLM TTFT

9router combo models (deepseek-v4-flash-free fallback) have TTFT up to
30-40s. Default (proxy) response_header_timeout 30s / read 60s caused
false-positive 504 'timeout awaiting response headers' even while 9router
was processing. Give the 9router route dedicated long timeouts
(response_header 120s, read/write 300s). Syncs /etc/caddy/Caddyfile.

infra/caddy/Caddyfile.prod

@@ -53,7 +53,23 @@ tools.asepharyana.my.id, tools.asepharyana.web.id {
 
 9router.asepharyana.my.id {
 	# LLM streaming: 9router combo models punya TTFT sampe 30-40s (deepseek,
-}
+	# fallback chain). Default (proxy) response_header_timeout 30s / read 60s
+	# bikin false-positive 504 walau 9router masih ngolah. Longgarkan khusus
+	# biar health-check & request PR-Agent real gak kena timeout transient.
+	encode zstd gzip
+	header {
+		-Server
+		X-Content-Type-Options "nosniff"
+	}
+	reverse_proxy 127.0.0.1:4014 {
+		transport http {
+			dial_timeout 3s
+			response_header_timeout 120s
+			read_timeout 300s
+			write_timeout 300s
+		}
+	}
+}
 
 pr-agent.asepharyana.my.id {
 	import proxy 4002