refactor(auth): replace TokenRecord with coreauth.Auth and migrate TokenStore to coreauth.Store

- Replaced `TokenRecord` with `coreauth.Auth` for centralized and consistent authentication data structures.
- Migrated `TokenStore` interface to `coreauth.Store` for alignment with core CLIProxy authentication.
- Updated related login methods, token persistence logic, and file storage handling to use the new `coreauth.Auth` model.

sdk/cliproxy/auth/manager.go

@@ -818,7 +818,8 @@ func (m *Manager) persist(ctx context.Context, auth *Auth) error {
 	if auth.Metadata == nil {
 		return nil
 	}
-	return m.store.SaveAuth(ctx, auth)
+	_, err := m.store.Save(ctx, auth)
+	return err
 }
 
 // StartAutoRefresh launches a background loop that evaluates auth freshness

sdk/cliproxy/auth/store.go

@@ -6,8 +6,8 @@ import "context"
 type Store interface {
 	// List returns all auth records stored in the backend.
 	List(ctx context.Context) ([]*Auth, error)
-	// SaveAuth persists the provided auth record, replacing any existing one with same ID.
-	SaveAuth(ctx context.Context, auth *Auth) error
+	// Save persists the provided auth record, replacing any existing one with same ID.
+	Save(ctx context.Context, auth *Auth) (string, error)
 	// Delete removes the auth record identified by id.
 	Delete(ctx context.Context, id string) error
 }

sdk/cliproxy/auth/types.go

@@ -6,6 +6,8 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	baseauth "github.com/router-for-me/CLIProxyAPI/v6/internal/auth"
 )
 
 // Auth encapsulates the runtime state and metadata associated with a single credential.
@@ -14,6 +16,10 @@ type Auth struct {
 	ID string `json:"id"`
 	// Provider is the upstream provider key (e.g. "gemini", "claude").
 	Provider string `json:"provider"`
+	// FileName stores the relative or absolute path of the backing auth file.
+	FileName string `json:"-"`
+	// Storage holds the token persistence implementation used during login flows.
+	Storage baseauth.TokenStorage `json:"-"`
 	// Label is an optional human readable label for logging.
 	Label string `json:"label,omitempty"`
 	// Status is the lifecycle status managed by the AuthManager.