feat: scaffold cortex workspace

Rust reverse-proxy for multi-node mistral.rs inference clusters.
Includes crate structure (cortex-core, cortex-gateway, cortex-agent,
cortex-cli), config loading, OpenAI/Anthropic translation stubs,
model routing, eviction, polling, and streaming proxy scaffolding.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/cortex-core/src/anthropic.rs

@@ -0,0 +1,87 @@
+//! Anthropic Messages API request and response types.
+//!
+//! These mirror the `/v1/messages` format used by the Anthropic API.
+//! The gateway accepts these, translates to OpenAI format, proxies to
+//! mistral.rs, then translates the response back.
+
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+
+// ── Messages request ─────────────────────────────────────────────────
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MessagesRequest {
+    pub model: String,
+    pub messages: Vec<AnthropicMessage>,
+    pub max_tokens: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub system: Option<SystemPrompt>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub temperature: Option<f64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub top_p: Option<f64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub stream: Option<bool>,
+    #[serde(flatten)]
+    pub extra: Value,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(untagged)]
+pub enum SystemPrompt {
+    Text(String),
+    Blocks(Vec<Value>),
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AnthropicMessage {
+    pub role: String,
+    pub content: AnthropicContent,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(untagged)]
+pub enum AnthropicContent {
+    Text(String),
+    Blocks(Vec<ContentBlock>),
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ContentBlock {
+    #[serde(rename = "type")]
+    pub block_type: String,
+    #[serde(flatten)]
+    pub data: Value,
+}
+
+// ── Messages response ────────────────────────────────────────────────
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MessagesResponse {
+    pub id: String,
+    #[serde(rename = "type")]
+    pub response_type: String,
+    pub role: String,
+    pub content: Vec<ContentBlock>,
+    pub model: String,
+    pub stop_reason: Option<String>,
+    pub usage: AnthropicUsage,
+    #[serde(flatten)]
+    pub extra: Value,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AnthropicUsage {
+    pub input_tokens: u64,
+    pub output_tokens: u64,
+}
+
+// ── Streaming events ─────────────────────────────────────────────────
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct StreamEvent {
+    #[serde(rename = "type")]
+    pub event_type: String,
+    #[serde(flatten)]
+    pub data: Value,
+}