fix(provider): 将rust分支的gemini cli端点行为对齐到python分支 (#321)

* fix(provider): 对齐 Vertex/Gemini 上游发包与 Python master

- provider-transport: 为 custom+aiplatform 推断 Vertex API key 上下文并统一 URL 构建顺序，复用共享 request_url 构建最终上游地址
- ai-pipeline/gateway: Vertex Gemini 路径改为仅使用 URL query key，不再向上游附带 x-goog-api-key header；同步对齐 standard/admin/test-connection/runtime miss 摘要中的最终 URL
- gemini conversion: 按 Python master 输出 Gemini 请求体，补齐 system_instruction / generation_config / tool_config / function_declarations 形态，并移植 Gemini schema 清洗逻辑
- scheduler/executor: 将最终 upstream_url、mapped_model、key_name 写入候选 extra_data，运行时 miss 诊断优先展示真实展开后的上游 URL 便于服务器排障

* fix(provider): 修复 Vertex provider 测试与本地调度链路

* fix(provider): 对齐 Vertex 本地执行与 Rust CI

crates/aether-provider-transport/src/lib.rs

@@ -10,6 +10,7 @@ mod network;
 pub mod oauth_refresh;
 pub mod policy;
 pub mod provider_types;
+mod request_url;
 pub mod rules;
 pub mod snapshot;
 pub mod url;
@@ -40,6 +41,7 @@ pub use policy::{
     local_standard_transport_unsupported_reason_with_network, supports_local_gemini_transport,
     supports_local_gemini_transport_with_network, supports_local_standard_transport,
 };
+pub use request_url::{build_transport_request_url, TransportRequestUrlParams};
 pub use rules::{
     apply_local_body_rules, apply_local_header_rules, body_rules_are_locally_supported,
     body_rules_handle_path, header_rules_are_locally_supported,
@@ -48,6 +50,7 @@ pub use snapshot::{
     read_provider_transport_snapshot, GatewayProviderTransportSnapshot,
     ProviderTransportSnapshotSource,
 };
+pub use vertex::{is_vertex_api_key_transport_context, uses_vertex_api_key_query_auth};
 pub use video::{
     reconstruct_local_video_task_snapshot, resolve_local_video_task_transport,
     VideoTaskTransportSnapshotLookup,