feat(observability): add structured application logging

Emit correlated JSON logs from the API and FunASR services, propagate request IDs to the client, and configure bounded opt-in Docker logging.

Document the host-wide Grafana/Loki query workflow and keep observability deployment ownership outside the application repository.

compose.deploy.yml

@@ -1,7 +1,19 @@
 name: teaching-feedback
 
 x-api-base: &api-base
-  image: teaching-feedback-api:0.1.0
+  image: teaching-feedback-api:${APP_VERSION:-0.2.0}
+
+x-default-logging: &default-logging
+  driver: local
+  options:
+    max-size: "20m"
+    max-file: "5"
+
+x-observability-labels: &observability-labels
+  observability.logs: "true"
+  observability.application: "teaching-feedback"
+  observability.environment: "lan"
+  observability.app_version: "${APP_VERSION:-0.2.0}"
 
 services:
   funasr:
@@ -12,7 +24,13 @@ services:
       args:
         DEBIAN_MIRROR: http://mirrors.ustc.edu.cn
         PYPI_INDEX_URL: https://mirrors.ustc.edu.cn/pypi/simple
+        APP_VERSION: ${APP_VERSION:-0.2.0}
+        GIT_SHA: ${GIT_SHA:-unknown}
     environment:
+      APP_ENV: lan
+      APP_VERSION: ${APP_VERSION:-0.2.0}
+      GIT_SHA: ${GIT_SHA:-unknown}
+      LOG_FORMAT: json
       ASR_MODEL: paraformer-zh
       ASR_VAD_MODEL: fsmn-vad
       ASR_PUNC_MODEL: ct-punc
@@ -20,6 +38,8 @@ services:
       ASR_MAX_CONCURRENCY: "1"
       ASR_BATCH_SIZE_SECONDS: "300"
       MODELSCOPE_CACHE: /models
+    labels: *observability-labels
+    logging: *default-logging
     volumes:
       - funasr-model-cache:/models
     restart: unless-stopped
@@ -40,6 +60,13 @@ services:
     <<: *api-base
     env_file:
       - ./server/.env
+    environment:
+      APP_ENV: lan
+      APP_VERSION: ${APP_VERSION:-0.2.0}
+      GIT_SHA: ${GIT_SHA:-unknown}
+      LOG_FORMAT: json
+    labels: *observability-labels
+    logging: *default-logging
     command:
       - migrate
     restart: "no"
@@ -53,9 +80,15 @@ services:
       dockerfile: Dockerfile
       args:
         DEBIAN_MIRROR: http://mirrors.ustc.edu.cn
+        APP_VERSION: ${APP_VERSION:-0.2.0}
+        GIT_SHA: ${GIT_SHA:-unknown}
     env_file:
       - ./server/.env
     environment:
+      APP_ENV: lan
+      APP_VERSION: ${APP_VERSION:-0.2.0}
+      GIT_SHA: ${GIT_SHA:-unknown}
+      LOG_FORMAT: json
       HOST: 0.0.0.0
       PORT: "8080"
       AUDIO_STORAGE_DIR: /data/audio
@@ -66,6 +99,8 @@ services:
       ASR_JOB_LEASE_SECONDS: "3600"
       DATABASE_MAX_CONNECTIONS: "5"
       ALLOW_DEVELOPMENT_USER_HEADER: "false"
+    labels: *observability-labels
+    logging: *default-logging
     ports:
       - "39180:8080"
     volumes: