feat(llm-api): add CI/CD, Dockerfile, compose, Traefik routing

- infra/docker/llm-api.Dockerfile — multi-stage Rust build with cargo-chef
- infra/compose/llm-api.yml — service with model volume mount & healthcheck
- infra/traefik/dynamic/apps.yaml — router for ai.asepharyana.my.id
- CI: build-push workflow detects llm-api changes, builds image
- CD: deploy workflow includes llm-api.yml in compose stack

infra/traefik/dynamic/apps.yaml

@@ -42,6 +42,14 @@ http:
       rule: Host(`auth.asepharyana.my.id`) || Host(`auth.asepharyana.web.id`)
       service: rust-auth-service
       tls: {}
+    llm-api:
+      entryPoints:
+      - websecure
+      middlewares:
+      - common-chain@file
+      rule: Host(`ai.asepharyana.my.id`) || Host(`ai.asepharyana.web.id`)
+      service: llm-api-service
+      tls: {}
     scraper:
       entryPoints:
       - websecure
@@ -76,6 +84,10 @@ http:
       loadBalancer:
         servers:
         - url: http://rust-auth:3000
+    llm-api-service:
+      loadBalancer:
+        servers:
+        - url: http://llm-api:8080
     scraper-service:
       loadBalancer:
         servers: