fix: resolve all linting and formatting issues

- Fix error return value checks (errcheck)
- Fix unused parameters by using underscore prefix
- Add missing package comments to all packages
- Fix context key type issue in middleware (use typed contextKey)
- Replace deprecated trace.NewNoopTracerProvider with noop.NewTracerProvider
- Fix embedded field selector in database client
- Remove trailing whitespace
- Remove revive linter (as requested) to avoid stuttering warnings for public API interfaces

All linting and formatting checks now pass.

internal/server/middleware.go

@@ -1,3 +1,4 @@
+// Package server provides HTTP middleware functions for request processing.
 package server
 
 import (
@@ -6,15 +7,17 @@ import (
 	"runtime"
 	"time"
 
-	"github.com/gin-gonic/gin"
-	"github.com/google/uuid"
 	"git.dcentral.systems/toolz/goplt/pkg/errorbus"
 	"git.dcentral.systems/toolz/goplt/pkg/logger"
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
 )
 
+type contextKey string
+
 const (
-	requestIDKey = "request_id"
-	userIDKey    = "user_id"
+	requestIDKey contextKey = "request_id"
+	userIDKey    contextKey = "user_id"
 )
 
 // RequestIDMiddleware generates a unique request ID for each request.
@@ -25,7 +28,7 @@ func RequestIDMiddleware() gin.HandlerFunc {
 			requestID = uuid.New().String()
 		}
 
-		c.Set(requestIDKey, requestID)
+		c.Set(string(requestIDKey), requestID)
 		c.Header("X-Request-ID", requestID)
 		c.Next()
 	}
@@ -45,7 +48,7 @@ func LoggingMiddleware(log logger.Logger) gin.HandlerFunc {
 		duration := time.Since(start)
 
 		// Get request ID from context
-		requestID, _ := c.Get(requestIDKey)
+		requestID, _ := c.Get(string(requestIDKey))
 		requestIDStr := ""
 		if id, ok := requestID.(string); ok {
 			requestIDStr = id
@@ -74,8 +77,8 @@ func PanicRecoveryMiddleware(errorBus errorbus.ErrorPublisher) gin.HandlerFunc {
 				stack = stack[:n]
 
 				// Get request ID from context
-				requestID, _ := c.Get(requestIDKey)
-				ctx := context.WithValue(context.Background(), "request_id", requestID)
+				requestID, _ := c.Get(string(requestIDKey))
+				ctx := context.WithValue(context.Background(), requestIDKey, requestID)
 
 				// Create error
 				var panicErr error
@@ -138,4 +141,3 @@ func TimeoutMiddleware(timeout time.Duration) gin.HandlerFunc {
 		c.Next()
 	}
 }
-