refactor: 调度器迁移至独立模块，消除 services->api 反向依赖

- 将调度器相关模块从 src/services/cache/ 迁移到 src/services/scheduling/
- 下沉类型定义到 core 层: AccessRestrictions, ProviderAuthInfo, ParsedChunk/StreamStats, 视频工具函数
- 提取 thinking_cache 签名缓存到 core/api_format/conversion/
- 提取 provider 认证逻辑到 services/provider/auth
- 提取遥测记录到 services/usage/telemetry
- 提取 models 列表缓存到 services/cache/model_list_cache
- 更新所有引用方的 import 路径及相关测试

src/services/orchestration/candidate_resolver.py

@@ -13,8 +13,8 @@ from sqlalchemy.orm import Session
 from src.core.exceptions import ProviderNotAvailableException
 from src.core.logger import logger
 from src.models.database import ApiKey
-from src.services.cache.aware_scheduler import CacheAwareScheduler, ProviderCandidate
 from src.services.provider.format import normalize_endpoint_signature
+from src.services.scheduling.aware_scheduler import CacheAwareScheduler, ProviderCandidate
 
 
 class CandidateResolver:

src/services/orchestration/error_classifier.py

@@ -25,9 +25,9 @@ from src.core.exceptions import (
 )
 from src.core.logger import logger
 from src.models.database import Provider, ProviderAPIKey, ProviderEndpoint
-from src.services.cache.aware_scheduler import CacheAwareScheduler
 from src.services.orchestration.error_handler import ErrorHandlerService
 from src.services.rate_limit.adaptive_rpm import get_adaptive_rpm_manager
+from src.services.scheduling.aware_scheduler import CacheAwareScheduler
 
 
 class ErrorAction(Enum):

src/services/orchestration/error_handler.py

@@ -22,11 +22,11 @@ from src.core.exceptions import (
 )
 from src.core.logger import logger
 from src.models.database import Provider, ProviderAPIKey, ProviderEndpoint
-from src.services.cache.aware_scheduler import CacheAwareScheduler
 from src.services.health.monitor import health_monitor
 from src.services.provider.format import normalize_endpoint_signature
 from src.services.rate_limit.adaptive_rpm import get_adaptive_rpm_manager
 from src.services.rate_limit.detector import RateLimitType, detect_rate_limit_type
+from src.services.scheduling.aware_scheduler import CacheAwareScheduler
 
 
 class ErrorHandlerService:

src/services/orchestration/request_dispatcher.py

@@ -11,9 +11,9 @@ from sqlalchemy.orm import Session
 
 from src.core.logger import logger
 from src.models.database import ApiKey
-from src.services.cache.aware_scheduler import CacheAwareScheduler, ProviderCandidate
 from src.services.request.candidate import RequestCandidateService
 from src.services.request.executor import RequestExecutor
+from src.services.scheduling.aware_scheduler import CacheAwareScheduler, ProviderCandidate
 
 
 class RequestDispatcher: