🔧 config: add log output file configuration and cleanup example files

config.yaml

@@ -1,5 +1,58 @@
+# DanceLessonsCoach Configuration
+# This file serves as both the default configuration and documentation
+# All available options are shown with their default values
+
+# Server configuration
 server:
+  # Host address to bind to (default: "0.0.0.0")
   host: "0.0.0.0"
+  
+  # Port to listen on (default: 8080)
   port: 8080
+
+# Shutdown configuration
 shutdown:
-  timeout: 5s
+  # Timeout duration for graceful shutdown (default: 30s)
+  # Format: number + unit (s, m, h)
+  timeout: 30s
+
+# Logging configuration
+logging:
+  # Enable JSON output for structured logging (default: false)
+  # When true, logs are output in JSON format instead of console format
+  json: false
+  
+  # Log level (default: "trace")
+  # Options: "trace", "debug", "info", "warn", "error", "fatal", "panic"
+  level: trace
+  
+  # Log output file path (default: "" for stderr)
+  # If empty, logs will be written to stderr
+  # If specified, logs will be written to the specified file
+  # Example: "server.log" or "/var/log/dance-lessons-coach.log"
+  output: ""
+
+# Telemetry configuration (OpenTelemetry)
+telemetry:
+  # Enable OpenTelemetry tracing (default: false)
+  enabled: false
+  
+  # OTLP endpoint for trace export (default: "localhost:4317")
+  # Format: host:port
+  otlp_endpoint: "localhost:4317"
+  
+  # Service name for tracing (default: "DanceLessonsCoach")
+  service_name: "DanceLessonsCoach"
+  
+  # Use insecure connection (no TLS) (default: true)
+  insecure: true
+  
+  # Sampler configuration
+  sampler:
+    # Sampler type (default: "parentbased_always_on")
+    # Options: "always_on", "always_off", "traceidratio", "parentbased_always_on", "parentbased_always_off", "parentbased_traceidratio"
+    type: "parentbased_always_on"
+    
+    # Sampling ratio (0.0 to 1.0, default: 1.0)
+    # Only used with traceidratio and parentbased_traceidratio samplers
+    ratio: 1.0