refactor(logging): replace all print/log with structured slog logger

- main.go: 30+ log.Printf → logger.Infof
- plugin/registry: 12 log.Printf → logger.Infof
- db/db.go, ws/hub.go: log → logger
- platform-bridge: fmt.Printf/println → logger.Info
- Logs now: time=... level=INFO msg=...
- 16 packages pass, vet clean

backend/internal/plugin/registry.go

@@ -3,7 +3,7 @@ package plugin
 import (
 	"context"
 	"fmt"
-	"log"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
 	"sync"
 )
 
@@ -36,7 +36,7 @@ func (r *Registry) Register(p Plugin, cfg PluginConfig) error {
 	}
 
 	if !p.Enabled() {
-		log.Printf("[plugin] %s is disabled, skipping", p.Name())
+		logger.Infof("[plugin] %s is disabled, skipping", p.Name())
 		return nil
 	}
 
@@ -53,18 +53,18 @@ func (r *Registry) Register(p Plugin, cfg PluginConfig) error {
 	// Auto-detect provider interfaces
 	if iot, ok := p.(IoTProvider); ok {
 		r.iotProviders = append(r.iotProviders, iot)
-		log.Printf("[plugin] registered IoT provider: %s v%s", p.Name(), p.Version())
+		logger.Infof("[plugin] registered IoT provider: %s v%s", p.Name(), p.Version())
 	}
 	if tool, ok := p.(ToolProvider); ok {
 		r.toolProviders = append(r.toolProviders, tool)
-		log.Printf("[plugin] registered tool provider: %s v%s (%d tools)", p.Name(), p.Version(), len(tool.Tools()))
+		logger.Infof("[plugin] registered tool provider: %s v%s (%d tools)", p.Name(), p.Version(), len(tool.Tools()))
 	}
 	if rag, ok := p.(RAGProvider); ok {
 		r.ragProviders = append(r.ragProviders, rag)
-		log.Printf("[plugin] registered RAG provider: %s v%s", p.Name(), p.Version())
+		logger.Infof("[plugin] registered RAG provider: %s v%s", p.Name(), p.Version())
 	}
 
-	log.Printf("[plugin] %s v%s loaded successfully", p.Name(), p.Version())
+	logger.Infof("[plugin] %s v%s loaded successfully", p.Name(), p.Version())
 	return nil
 }
 
@@ -166,27 +166,27 @@ func (r *Registry) Shutdown() {
 			continue
 		}
 		if err := p.Close(); err != nil {
-			log.Printf("[plugin] error closing %s: %v", p.Name(), err)
+			logger.Infof("[plugin] error closing %s: %v", p.Name(), err)
 		}
 	}
 
 	// Close IoT providers
 	for _, p := range r.iotProviders {
 		if err := p.Close(); err != nil {
-			log.Printf("[plugin] error closing %s: %v", p.Name(), err)
+			logger.Infof("[plugin] error closing %s: %v", p.Name(), err)
 		}
 	}
 	// Close tool providers
 	for _, p := range r.toolProviders {
 		if err := p.Close(); err != nil {
-			log.Printf("[plugin] error closing %s: %v", p.Name(), err)
+			logger.Infof("[plugin] error closing %s: %v", p.Name(), err)
 		}
 	}
 	// Close RAG providers
 	for _, p := range r.ragProviders {
 		if err := p.Close(); err != nil {
-			log.Printf("[plugin] error closing %s: %v", p.Name(), err)
+			logger.Infof("[plugin] error closing %s: %v", p.Name(), err)
 		}
 	}
-	log.Printf("[plugin] all plugins shut down")
+	logger.Infof("[plugin] all plugins shut down")
 }