REFACTOR(loki,tempo): switch from MinIO to local-path storage

- Loki: s3 backend to filesystem with local-path PVC
- Tempo: s3 backend to local backend with local-path PVC
- Remove MinIO/S3 credentials and configuration

tempo/helm-values.yaml

@@ -3,7 +3,7 @@
 #
 # Architecture:
 # - Single binary (monolithic) mode for small clusters
-# - MinIO S3 for trace storage
+# - Local filesystem for trace storage
 # - OTLP receiver for OpenTelemetry data
 # - Integrates with Grafana for trace visualization
 
@@ -41,17 +41,14 @@ tempo:
   # Retention settings
   retention: 72h  # Keep traces for 3 days
 
-  # Backend storage (MinIO S3)
-  # Uses environment variable expansion
+  # Backend storage (local filesystem)
   storage:
     trace:
-      backend: s3
-      s3:
-        bucket: tempo
-        endpoint: minio.minio.svc.cluster.local:9000
-        access_key: ${S3_ACCESS_KEY}
-        secret_key: ${S3_SECRET_KEY}
-        insecure: true
+      backend: local
+      local:
+        path: /var/tempo/traces
+      wal:
+        path: /var/tempo/wal
 
   # Query settings
   querier:
@@ -63,30 +60,13 @@ tempo:
     enabled: true
     remoteWriteUrl: http://prometheus-kube-prometheus-prometheus.prometheus.svc:9090/api/v1/write
 
-  # Enable environment variable expansion in config
-  extraArgs:
-    config.expand-env: "true"
-
-  # Environment variables from secret for S3 credentials
-  extraEnv:
-    - name: S3_ACCESS_KEY
-      valueFrom:
-        secretKeyRef:
-          name: tempo-s3-secret
-          key: S3_ACCESS_KEY
-    - name: S3_SECRET_KEY
-      valueFrom:
-        secretKeyRef:
-          name: tempo-s3-secret
-          key: S3_SECRET_KEY
-
 # =============================================================================
-# Persistence (local cache)
+# Persistence (local-path PVC)
 # =============================================================================
 persistence:
   enabled: true
   storageClassName: local-path
-  size: 2Gi
+  size: 5Gi
 
 # =============================================================================
 # Service