feat(provider): add google project and location fields

Add support for Google Cloud-specific configuration in provider models.
New fields `GoogleProject` and `GoogleLocation` are now included in the
Provider DTO, database model, API handlers, and sync service snapshots.

- Extend Provider struct in model with gorm/json tags
- Update ProviderDTO with omitempty JSON tags
- Include fields in handler create/update logic with trim
- Add fields to providerSnapshot for sync operations

internal/api/handler.go

@@ -62,6 +62,8 @@ func (h *Handler) CreateProvider(c *gin.Context) {
 		Type:           req.Type,
 		BaseURL:        req.BaseURL,
 		APIKey:         req.APIKey,
+		GoogleProject:  strings.TrimSpace(req.GoogleProject),
+		GoogleLocation: strings.TrimSpace(req.GoogleLocation),
 		Group:          group,
 		Models:         strings.Join(req.Models, ","),
 		Status:         status,
@@ -133,6 +135,12 @@ func (h *Handler) UpdateProvider(c *gin.Context) {
 	if req.APIKey != "" {
 		update["api_key"] = req.APIKey
 	}
+	if strings.TrimSpace(req.GoogleProject) != "" {
+		update["google_project"] = strings.TrimSpace(req.GoogleProject)
+	}
+	if strings.TrimSpace(req.GoogleLocation) != "" {
+		update["google_location"] = strings.TrimSpace(req.GoogleLocation)
+	}
 	if req.Models != nil {
 		update["models"] = strings.Join(req.Models, ",")
 	}

internal/dto/provider.go

@@ -8,6 +8,8 @@ type ProviderDTO struct {
 	Type           string    `json:"type"`
 	BaseURL        string    `json:"base_url"`
 	APIKey         string    `json:"api_key"`
+	GoogleProject  string    `json:"google_project,omitempty"`
+	GoogleLocation string    `json:"google_location,omitempty"`
 	Group          string    `json:"group"`
 	Models         []string  `json:"models"` // List of supported model names
 	Status         string    `json:"status"`

internal/model/models.go

@@ -40,6 +40,8 @@ type Provider struct {
 	Type           string     `gorm:"not null" json:"type"` // openai, anthropic, etc.
 	BaseURL        string     `json:"base_url"`
 	APIKey         string     `json:"api_key"`
+	GoogleProject  string     `gorm:"size:128" json:"google_project,omitempty"`
+	GoogleLocation string     `gorm:"size:64" json:"google_location,omitempty"`
 	Group          string     `gorm:"default:'default'" json:"group"`         // routing group/tier
 	Models         string     `json:"models"`                                 // comma-separated list of supported models (e.g. "gpt-4,gpt-3.5-turbo")
 	Status         string     `gorm:"size:50;default:'active'" json:"status"` // active, auto_disabled, manual_disabled

internal/service/sync.go

@@ -71,6 +71,8 @@ func (s *SyncService) SyncProvider(provider *model.Provider) error {
 		Type:           provider.Type,
 		BaseURL:        provider.BaseURL,
 		APIKey:         provider.APIKey,
+		GoogleProject:  provider.GoogleProject,
+		GoogleLocation: provider.GoogleLocation,
 		Group:          group,
 		Models:         models,
 		Status:         normalizeStatus(provider.Status),
@@ -129,6 +131,8 @@ type providerSnapshot struct {
 	Type           string   `json:"type"`
 	BaseURL        string   `json:"base_url"`
 	APIKey         string   `json:"api_key"`
+	GoogleProject  string   `json:"google_project,omitempty"`
+	GoogleLocation string   `json:"google_location,omitempty"`
 	Group          string   `json:"group"`
 	Models         []string `json:"models"`
 	Status         string   `json:"status"`
@@ -203,6 +207,8 @@ func (s *SyncService) SyncAll(db *gorm.DB) error {
 			Type:           p.Type,
 			BaseURL:        p.BaseURL,
 			APIKey:         p.APIKey,
+			GoogleProject:  p.GoogleProject,
+			GoogleLocation: p.GoogleLocation,
 			Group:          group,
 			Models:         models,
 			Status:         normalizeStatus(p.Status),