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 <53283266+Entropy-Xu@users.noreply.github.com>

crates/aether-model-fetch/src/logic.rs

@@ -251,7 +251,13 @@ pub fn preset_models_for_provider(provider_type: &str) -> Option<Vec<Value>> {
         ],
         "codex" => vec![
             preset_model("gpt-5", "openai", "GPT-5", "openai:cli"),
+            preset_model("gpt-image-1", "openai", "GPT Image 1", "openai:image"),
+            preset_model("gpt-image-1.5", "openai", "GPT Image 1.5", "openai:image"),
+            preset_model("gpt-image-1-mini", "openai", "GPT Image 1 Mini", "openai:image"),
             preset_model("gpt-image-2", "openai", "GPT Image 2", "openai:image"),
+            preset_model("chatgpt-image-latest", "openai", "ChatGPT Image Latest", "openai:image"),
+            preset_model("dall-e-2", "openai", "DALL-E 2", "openai:image"),
+            preset_model("dall-e-3", "openai", "DALL-E 3", "openai:image"),
             preset_model("gpt-5-codex", "openai", "GPT-5 Codex", "openai:cli"),
             preset_model("gpt-5-codex-mini", "openai", "GPT-5 Codex Mini", "openai:cli"),
             preset_model("gpt-5.1", "openai", "GPT-5.1", "openai:cli"),