refactor: 移除独立 hub/proxy/executor/gateway crate，统一为 gateway tunnel 架构

- 删除 aether-hub、aether-proxy 独立项目及其 Dockerfile/配置
- 删除 crates/aether-executor 和 crates/aether-gateway 全部模块
- 新增 apps/ 目录作为应用入口
- 将 hub 概念重构为 gateway tunnel transport
- 将 executor 重构为 execution runtime
- 新增 tunnel.rs 合约定义和 testkit tunnel/execution_runtime 模块
- 更新 Python 服务层和测试适配新架构命名

apps/aether-gateway/src/video_tasks/mod.rs

@@ -0,0 +1,57 @@
+use std::collections::BTreeMap;
+use std::path::{Path, PathBuf};
+use std::sync::{Arc, Mutex};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use aether_contracts::{ExecutionPlan, ExecutionTimeouts, ProxySnapshot, RequestBody};
+use aether_data::repository::video_tasks::{
+    StoredVideoTask, UpsertVideoTask, VideoTaskStatus as StoredVideoTaskStatus,
+};
+use serde::{Deserialize, Serialize};
+use serde_json::{json, Map, Value};
+use uuid::Uuid;
+
+use crate::gateway::provider_transport::{
+    resolve_local_gemini_auth, resolve_local_standard_auth, resolve_transport_execution_timeouts,
+    supports_local_gemini_transport, supports_local_standard_transport,
+    GatewayProviderTransportSnapshot,
+};
+use crate::gateway::GatewayControlAuthContext;
+
+const DEFAULT_VIDEO_TASK_POLL_INTERVAL_SECONDS: u32 = 10;
+const DEFAULT_VIDEO_TASK_MAX_POLL_COUNT: u32 = 360;
+
+pub(crate) use self::service::VideoTaskService;
+pub use self::types::VideoTaskTruthSourceMode;
+pub(crate) use self::types::{
+    GeminiVideoTaskSeed, LocalVideoTaskContentAction, LocalVideoTaskFollowUpPlan,
+    LocalVideoTaskPersistence, LocalVideoTaskReadRefreshPlan, LocalVideoTaskReadResponse,
+    LocalVideoTaskRegistryMutation, LocalVideoTaskSeed, LocalVideoTaskSnapshot,
+    LocalVideoTaskStatus, LocalVideoTaskSuccessPlan, LocalVideoTaskTransport, OpenAiVideoTaskSeed,
+    VideoTaskSyncReportMode,
+};
+
+pub(crate) use self::helpers::{
+    extract_gemini_short_id_from_cancel_path, extract_gemini_short_id_from_path,
+    extract_openai_task_id_from_cancel_path, extract_openai_task_id_from_content_path,
+    extract_openai_task_id_from_path, extract_openai_task_id_from_remix_path,
+};
+
+use self::helpers::{
+    build_video_follow_up_report_context, context_text, context_u64, current_unix_timestamp_secs,
+    gemini_metadata_video_url, generate_local_short_id, local_status_from_stored,
+    map_openai_task_status, non_empty_owned, parse_video_content_variant, request_body_string,
+    request_body_text, request_body_u32, resolve_follow_up_auth,
+    resolve_local_video_registry_mutation,
+};
+use self::store::{FileVideoTaskStore, InMemoryVideoTaskStore, VideoTaskStore};
+use self::types::LocalVideoTaskProjectionTarget;
+
+mod helpers;
+mod seed;
+mod service;
+mod store;
+mod types;
+
+#[cfg(test)]
+mod tests;