feat: Round 5 - Memory Service, Tool Engine, Call Records, Thinking Logs

- Fix: Session history flash (race condition + WS guard)
- Fix: Chat background overlay + sidebar transparency
- Fix: IoT device control (Chinese action names, status field)
- Feat: Independent memory-service (port 8091, 13 endpoints)
- Feat: Independent tool-engine service (port 8092, 13 tools)
- Feat: Tool call logs with paginated DevTools panel
- Feat: Thinking log records with DevTools panel
- Feat: Future development roadmap document
- Chore: Updated .gitignore, go.work, DevTools config
- Chore: 5-service health check, project review docs

backend/memory-service/internal/config/config.go

@@ -0,0 +1,45 @@
+package config
+
+import (
+	"fmt"
+	"os"
+)
+
+// Config 记忆服务配置
+type Config struct {
+	Port        string
+	DatabaseURL string
+}
+
+// Load 从环境变量加载配置
+func Load() *Config {
+	return &Config{
+		Port:        getEnv("PORT", "8091"),
+		DatabaseURL: buildDatabaseURL(),
+	}
+}
+
+// buildDatabaseURL 构建 PostgreSQL 连接字符串
+func buildDatabaseURL() string {
+	// 优先使用 DB_URL 环境变量（简化模式）
+	if url := os.Getenv("DB_URL"); url != "" {
+		return url
+	}
+
+	host := getEnv("POSTGRES_HOST", "localhost")
+	port := getEnv("POSTGRES_PORT", "5432")
+	user := getEnv("POSTGRES_USER", "cyrene")
+	password := getEnv("POSTGRES_PASSWORD", "change_me")
+	dbname := getEnv("POSTGRES_DB", "cyrene_ai")
+	sslmode := getEnv("POSTGRES_SSLMODE", "disable")
+
+	return fmt.Sprintf("postgres://%s:%s@%s:%s/%s?sslmode=%s",
+		user, password, host, port, dbname, sslmode)
+}
+
+func getEnv(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}