feat: provider api_formats 可空继承、OpenAI 图片 edit/variation 与用量配额多项补强

- 鉴权: provider_api_keys.api_formats 改为可空，OAuth 托管 key 自动继承 provider endpoints 激活格式，相关 handler/测试同步更新
- 图片 planner: OpenAI 图片路由新增 edit/variation 操作并完善参数校验、响应合并与流式处理
- 用量: user me usage 返回区分 client_requested_stream/upstream_is_stream，前端 usage 列表筛选与展示增强
- 统计: stats_daily_model 新增 cache_creation_ephemeral_5m/1h tokens 字段与回填链路
- 配额/observability: quota repository 新增内存与 SQL 扩展，admin observability usage 字段扩充
- 其它: OAuth 导入/轮询收敛、provider 汇总与 pool admin 读写链路小修、新增 system_config 缓存与 provider template handler

Closes #318

Co-authored-by: Entropy.Xu <[email protected]>

apps/aether-gateway/src/executor/orchestration.rs

@@ -1,6 +1,7 @@
 use crate::ai_pipeline_api::{
     build_local_gemini_files_stream_plan_and_reports_for_kind,
     build_local_gemini_files_sync_plan_and_reports_for_kind,
+    build_local_image_stream_plan_and_reports_for_kind,
     build_local_image_sync_plan_and_reports_for_kind,
     build_local_openai_chat_stream_plan_and_reports_for_kind,
     build_local_openai_chat_sync_plan_and_reports_for_kind,
@@ -464,6 +465,33 @@ pub(crate) async fn maybe_execute_stream_via_local_gemini_files_decision(
     execute_stream_plan_and_reports(state, trace_id, decision, plan_kind, plan_and_reports).await
 }
 
+pub(crate) async fn maybe_execute_stream_via_local_image_decision(
+    state: &AppState,
+    parts: &http::request::Parts,
+    body_json: &serde_json::Value,
+    body_base64: Option<&str>,
+    trace_id: &str,
+    decision: &GatewayControlDecision,
+    plan_kind: &str,
+) -> Result<LocalExecutionRequestOutcome, GatewayError> {
+    let plan_and_reports: Vec<LocalStreamPlanAndReport> =
+        build_local_image_stream_plan_and_reports_for_kind(
+            state,
+            parts,
+            body_json,
+            body_base64,
+            trace_id,
+            decision,
+            plan_kind,
+        )
+        .await?;
+    if plan_and_reports.is_empty() {
+        return Ok(LocalExecutionRequestOutcome::NoPath);
+    }
+
+    execute_stream_plan_and_reports(state, trace_id, decision, plan_kind, plan_and_reports).await
+}
+
 pub(crate) async fn maybe_execute_sync_via_local_video_decision(
     state: &AppState,
     parts: &http::request::Parts,