feat(server): implement management endpoints and redis sync

Enable full resource management via API and support data plane
synchronization.

- Add CRUD handlers for Providers, Models, and Keys using DTOs
- Implement LogWriter service for asynchronous, batched audit logging
- Update SyncService to snapshot full configuration state to Redis
- Register new API routes and initialize background services
- Add configuration options for logging performance tuning

internal/model/log.go

@@ -0,0 +1,22 @@
+package model
+
+import "gorm.io/gorm"
+
+// LogRecord stores lightweight metadata for auditing. Avoids full payload unless audit is triggered.
+type LogRecord struct {
+	gorm.Model
+	Group        string `json:"group"`
+	KeyID        uint   `json:"key_id"`
+	ModelName    string `json:"model"`
+	StatusCode   int    `json:"status_code"`
+	LatencyMs    int64  `json:"latency_ms"`
+	TokensIn     int64  `json:"tokens_in"`
+	TokensOut    int64  `json:"tokens_out"`
+	ErrorMessage string `json:"error_message"`
+	ClientIP     string `json:"client_ip"`
+	RequestSize  int64  `json:"request_size"`
+	ResponseSize int64  `json:"response_size"`
+	AuditReason  string `json:"audit_reason"`
+	RequestBody  string `json:"request_body"`  // optional, only when audit triggered
+	ResponseBody string `json:"response_body"` // optional, only when audit triggered
+}

internal/model/models.go

@@ -6,32 +6,37 @@ import (
 
 type User struct {
 	gorm.Model
-	Username string `gorm:"uniqueIndex;not null"`
-	Quota    int64  `gorm:"default:0"`
-	Role     string `gorm:"default:'user'"` // admin, user
+	Username string `gorm:"uniqueIndex;not null" json:"username"`
+	Quota    int64  `gorm:"default:0" json:"quota"`
+	Role     string `gorm:"default:'user'" json:"role"` // admin, user
 }
 
 type Provider struct {
 	gorm.Model
-	Name    string `gorm:"not null"`
-	Type    string `gorm:"not null"` // openai, anthropic, etc.
-	BaseURL string
-	APIKey  string
+	Name    string `gorm:"not null" json:"name"`
+	Type    string `gorm:"not null" json:"type"` // openai, anthropic, etc.
+	BaseURL string `json:"base_url"`
+	APIKey  string `json:"api_key"`
 }
 
 type Key struct {
 	gorm.Model
-	ProviderID *uint
-	Provider   *Provider
-	KeySecret  string `gorm:"not null"`
-	Balance    float64
-	Status     string `gorm:"default:'active'"` // active, suspended
-	Weight     int    `gorm:"default:10"`
+	ProviderID *uint     `json:"provider_id"`
+	Provider   *Provider `json:"-"`
+	KeySecret  string    `gorm:"not null" json:"key_secret"`
+	Balance    float64   `json:"balance"`
+	Status     string    `gorm:"default:'active'" json:"status"` // active, suspended
+	Weight     int       `gorm:"default:10" json:"weight"`
 }
 
 type Model struct {
 	gorm.Model
-	Name          string `gorm:"uniqueIndex;not null"`
-	ContextWindow int
-	CostPerToken  float64
+	Name               string  `gorm:"uniqueIndex;not null" json:"name"`
+	ContextWindow      int     `json:"context_window"`
+	CostPerToken       float64 `json:"cost_per_token"`
+	SupportsVision     bool    `json:"supports_vision"`
+	SupportsFunctions  bool    `json:"supports_functions"`
+	SupportsToolChoice bool    `json:"supports_tool_choice"`
+	SupportsFIM        bool    `json:"supports_fim"`
+	MaxOutputTokens    int     `json:"max_output_tokens"`
 }