feat: 扩展 Rust gateway 全功能模块，新增 billing/crypto/wallet crate 及完整数据层

- 新增 aether-billing、aether-crypto、aether-wallet 独立 crate
- aether-data 扩展 repository 层：announcements、auth_modules、billing、
  candidate_selection、gemini_file_mappings、global_models、management_tokens、
  oauth_providers、proxy_nodes、quota、users、wallet 等模块
- aether-gateway 新增 api/auth/billing/control/middleware/scheduler/usage/
  video_tasks/hooks/maintenance/model_fetch/provider_transport 等功能模块
- 重构 executor decision 和 gateway state 为模块目录结构
- 新增 gateway router、frontdoor 路由层及对应测试
- Python 侧 API 路由重构，新增 compat/support 模块
- 前端 Logo 组件更新及 Provider 管理页面调整

crates/aether-billing/src/pricing.rs

@@ -0,0 +1,94 @@
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct BillingModelPricingSnapshot {
+    pub provider_id: String,
+    pub provider_billing_type: Option<String>,
+    pub provider_api_key_id: Option<String>,
+    pub provider_api_key_rate_multipliers: Option<Value>,
+    pub provider_api_key_cache_ttl_minutes: Option<i64>,
+    pub global_model_id: String,
+    pub global_model_name: String,
+    pub global_model_config: Option<Value>,
+    pub default_price_per_request: Option<f64>,
+    pub default_tiered_pricing: Option<Value>,
+    pub model_id: Option<String>,
+    pub model_provider_model_name: Option<String>,
+    pub model_config: Option<Value>,
+    pub model_price_per_request: Option<f64>,
+    pub model_tiered_pricing: Option<Value>,
+}
+
+impl BillingModelPricingSnapshot {
+    pub fn effective_tiered_pricing(&self) -> Option<&Value> {
+        self.model_tiered_pricing
+            .as_ref()
+            .or(self.default_tiered_pricing.as_ref())
+    }
+
+    pub fn effective_price_per_request(&self) -> Option<f64> {
+        self.model_price_per_request
+            .or(self.default_price_per_request)
+    }
+
+    pub fn is_free_tier(&self) -> bool {
+        self.provider_billing_type
+            .as_deref()
+            .map(|value| value.eq_ignore_ascii_case("free_tier"))
+            .unwrap_or(false)
+    }
+
+    pub fn rate_multiplier_for_api_format(&self, api_format: Option<&str>) -> f64 {
+        let Some(api_format) = api_format.map(str::trim).filter(|value| !value.is_empty()) else {
+            return 1.0;
+        };
+        let normalized = api_format.to_ascii_lowercase();
+        let Some(mapping) = self
+            .provider_api_key_rate_multipliers
+            .as_ref()
+            .and_then(Value::as_object)
+        else {
+            return 1.0;
+        };
+        mapping
+            .get(&normalized)
+            .and_then(|value| value.as_f64())
+            .unwrap_or(1.0)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct BillingUsageInput {
+    pub task_type: String,
+    pub api_format: Option<String>,
+    pub request_count: i64,
+    pub input_tokens: i64,
+    pub output_tokens: i64,
+    pub cache_creation_tokens: i64,
+    pub cache_read_tokens: i64,
+    pub cache_ttl_minutes: Option<i64>,
+}
+
+impl BillingUsageInput {
+    pub fn new(task_type: impl Into<String>) -> Self {
+        Self {
+            task_type: task_type.into(),
+            api_format: None,
+            request_count: 1,
+            input_tokens: 0,
+            output_tokens: 0,
+            cache_creation_tokens: 0,
+            cache_read_tokens: 0,
+            cache_ttl_minutes: None,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct BillingComputation {
+    pub cost_result: crate::CostResult,
+    pub actual_total_cost: f64,
+    pub rate_multiplier: f64,
+    pub is_free_tier: bool,
+}