fix(infra): move Redis to prod, fix LibreTranslate config loading

- Add Redis sidecar to prod docker-compose; backend connects locally (redis:6379)
- Caddy layer4 now proxies redis.libnovel.cc:6380 → local redis:6379 (not homelab LAN)
- Remove HOMELAB_REDIS_ADDR; homelab runner connects out to prod Redis via rediss://
- Remove local Redis from homelab runner compose; drop redis_data volume
- Fix config.Load() missing LibreTranslate section — LIBRETRANSLATE_URL was never read

homelab/runner/docker-compose.yml

@@ -11,25 +11,10 @@
 #   - MEILI_URL               → https://search.libnovel.cc (Caddy-proxied)
 #   - VALKEY_ADDR             → unset (not exposed publicly)
 #   - RUNNER_SKIP_INITIAL_CATALOGUE_REFRESH=true
-#   - Redis service for Asynq task queue (local to homelab, exposed to prod via Caddy TCP proxy)
+#   - REDIS_ADDR              → rediss://redis.libnovel.cc:6380 (prod Redis via Caddy TLS proxy)
 #   - LibreTranslate service for machine translation (internal network only)
 
 services:
-  redis:
-    image: redis:7-alpine
-    restart: unless-stopped
-    volumes:
-      - redis_data:/data
-    command: >
-      redis-server
-      --appendonly yes
-      --requirepass "${REDIS_PASSWORD}"
-    healthcheck:
-      test: ["CMD", "redis-cli", "-a", "${REDIS_PASSWORD}", "ping"]
-      interval: 10s
-      timeout: 5s
-      retries: 5
-
   libretranslate:
     image: libretranslate/libretranslate:latest
     restart: unless-stopped
@@ -55,8 +40,6 @@ services:
     restart: unless-stopped
     stop_grace_period: 135s
     depends_on:
-      redis:
-        condition: service_healthy
       libretranslate:
         condition: service_healthy
     environment:
@@ -91,9 +74,10 @@ services:
       LIBRETRANSLATE_URL: "http://libretranslate:5000"
       LIBRETRANSLATE_API_KEY: "${LIBRETRANSLATE_API_KEY}"
 
-      # ── Asynq / Redis (local service) ───────────────────────────────────────
-      # The runner connects to the local Redis sidecar.
-      REDIS_ADDR: "redis:6379"
+      # ── Asynq / Redis (prod Redis via Caddy TLS proxy) ──────────────────────
+      # The runner connects to prod Redis over TLS: rediss://redis.libnovel.cc:6380.
+      # Caddy on prod terminates TLS and proxies to the local redis:6379 sidecar.
+      REDIS_ADDR: "${REDIS_ADDR}"
       REDIS_PASSWORD: "${REDIS_PASSWORD}"
 
       # ── Runner tuning ───────────────────────────────────────────────────────
@@ -117,6 +101,5 @@ services:
       retries: 3
 
 volumes:
-  redis_data:
   libretranslate_models:
   libretranslate_db: