refactor: 大规模模块拆分与代码精简，新增 ai-pipeline/data-contracts 独立 crate

- 新增 aether-ai-pipeline 和 aether-data-contracts crate，将 pipeline 逻辑与数据契约从 gateway 中解耦
- 重构 admin handlers：拆分单体模块为 auth/billing/endpoint/features/model/observability/provider/system 等独立子模块
- 合并 chat/cli 重复代码路径：精简 conversion、finalize、planner 中的 sync/chat/cli 分支
- 重构 scheduler/executor/data 层，引入 facade 模式降低模块间耦合
- 移除冗余的 intent 模块，将 plan_fallback/policy/stream_path/sync_path 迁移至 executor
- 前端适配：调整 admin API 调用和 provider 模型测试对话框

apps/aether-gateway/src/handlers/admin/provider/endpoints_admin/payloads.rs

@@ -0,0 +1,146 @@
+use crate::handlers::admin::shared::unix_secs_to_rfc3339;
+use aether_data_contracts::repository::provider_catalog::{
+    StoredProviderCatalogEndpoint, StoredProviderCatalogKey,
+};
+use serde::Deserialize;
+use serde_json::json;
+use std::collections::BTreeMap;
+
+pub(super) fn key_api_formats_without_entry(
+    key: &StoredProviderCatalogKey,
+    api_format: &str,
+) -> Option<Vec<String>> {
+    let current_formats =
+        crate::handlers::admin::shared::json_string_list(key.api_formats.as_ref());
+    if !current_formats
+        .iter()
+        .any(|candidate| candidate == api_format)
+    {
+        return None;
+    }
+    Some(
+        current_formats
+            .into_iter()
+            .filter(|candidate| candidate != api_format)
+            .collect(),
+    )
+}
+
+pub(super) fn endpoint_key_counts_by_format(
+    keys: &[StoredProviderCatalogKey],
+) -> (BTreeMap<String, usize>, BTreeMap<String, usize>) {
+    let mut total = BTreeMap::new();
+    let mut active = BTreeMap::new();
+    for key in keys {
+        let Some(formats) = key
+            .api_formats
+            .as_ref()
+            .and_then(serde_json::Value::as_array)
+        else {
+            continue;
+        };
+        for api_format in formats.iter().filter_map(serde_json::Value::as_str) {
+            *total.entry(api_format.to_string()).or_insert(0) += 1;
+            if key.is_active {
+                *active.entry(api_format.to_string()).or_insert(0) += 1;
+            }
+        }
+    }
+    (total, active)
+}
+
+pub(super) fn build_admin_provider_endpoint_response(
+    endpoint: &StoredProviderCatalogEndpoint,
+    provider_name: &str,
+    total_keys: usize,
+    active_keys: usize,
+    now_unix_secs: u64,
+) -> serde_json::Value {
+    json!({
+        "id": endpoint.id,
+        "provider_id": endpoint.provider_id,
+        "provider_name": provider_name,
+        "api_format": endpoint.api_format,
+        "base_url": endpoint.base_url,
+        "custom_path": endpoint.custom_path,
+        "header_rules": endpoint.header_rules,
+        "body_rules": endpoint.body_rules,
+        "max_retries": endpoint.max_retries.unwrap_or(2),
+        "is_active": endpoint.is_active,
+        "config": endpoint.config,
+        "proxy": masked_proxy_value(endpoint.proxy.as_ref()),
+        "format_acceptance_config": endpoint.format_acceptance_config,
+        "total_keys": total_keys,
+        "active_keys": active_keys,
+        "created_at": endpoint_timestamp_or_now(endpoint.created_at_unix_secs, now_unix_secs),
+        "updated_at": endpoint_timestamp_or_now(endpoint.updated_at_unix_secs, now_unix_secs),
+    })
+}
+
+fn masked_proxy_value(proxy: Option<&serde_json::Value>) -> serde_json::Value {
+    let Some(proxy) = proxy.and_then(serde_json::Value::as_object) else {
+        return serde_json::Value::Null;
+    };
+    let mut masked = proxy.clone();
+    if masked
+        .get("password")
+        .and_then(serde_json::Value::as_str)
+        .is_some_and(|value| !value.trim().is_empty())
+    {
+        masked.insert("password".to_string(), json!("***"));
+    }
+    serde_json::Value::Object(masked)
+}
+
+fn endpoint_timestamp_or_now(value: Option<u64>, now_unix_secs: u64) -> serde_json::Value {
+    unix_secs_to_rfc3339(value.unwrap_or(now_unix_secs))
+        .map(serde_json::Value::String)
+        .unwrap_or(serde_json::Value::Null)
+}
+
+fn default_admin_endpoint_max_retries() -> i32 {
+    2
+}
+
+#[derive(Debug, Deserialize)]
+pub(super) struct AdminProviderEndpointCreateRequest {
+    pub(super) provider_id: String,
+    pub(super) api_format: String,
+    pub(super) base_url: String,
+    #[serde(default)]
+    pub(super) custom_path: Option<String>,
+    #[serde(default)]
+    pub(super) header_rules: Option<serde_json::Value>,
+    #[serde(default)]
+    pub(super) body_rules: Option<serde_json::Value>,
+    #[serde(default = "default_admin_endpoint_max_retries")]
+    pub(super) max_retries: i32,
+    #[serde(default)]
+    pub(super) config: Option<serde_json::Value>,
+    #[serde(default)]
+    pub(super) proxy: Option<serde_json::Value>,
+    #[serde(default)]
+    pub(super) format_acceptance_config: Option<serde_json::Value>,
+}
+
+#[derive(Debug, Deserialize)]
+pub(super) struct AdminProviderEndpointUpdateRequest {
+    #[serde(default)]
+    pub(super) base_url: Option<String>,
+    #[serde(default)]
+    pub(super) custom_path: Option<String>,
+    #[serde(default)]
+    pub(super) header_rules: Option<serde_json::Value>,
+    #[serde(default)]
+    pub(super) body_rules: Option<serde_json::Value>,
+    #[serde(default)]
+    pub(super) max_retries: Option<i32>,
+    #[serde(default)]
+    pub(super) is_active: Option<bool>,
+    #[serde(default)]
+    pub(super) config: Option<serde_json::Value>,
+    #[serde(default)]
+    pub(super) proxy: Option<serde_json::Value>,
+    #[serde(default)]
+    pub(super) format_acceptance_config: Option<serde_json::Value>,
+}