Add Maritime/Logistics support assistant with safety/eval layer

src/llm/messages.rs

@@ -0,0 +1,76 @@
+//! Request/response shapes for the Anthropic Messages API.
+//!
+//! Hand-rolled rather than pulled from an SDK: pydantic-ai has no Rust
+//! equivalent, and the surface area we actually need (text, tool_use,
+//! tool_result, forced tool choice) is small enough to own directly.
+
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Message {
+    pub role: String,
+    pub content: Vec<ContentBlock>,
+}
+
+impl Message {
+    pub fn user_text(text: impl Into<String>) -> Self {
+        Self {
+            role: "user".into(),
+            content: vec![ContentBlock::Text { text: text.into() }],
+        }
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum ContentBlock {
+    Text {
+        text: String,
+    },
+    ToolUse {
+        id: String,
+        name: String,
+        input: Value,
+    },
+    ToolResult {
+        tool_use_id: String,
+        content: String,
+    },
+    /// Anything else the API sends back (e.g. a `thinking` block) that this
+    /// client doesn't act on but must not fail to deserialize.
+    #[serde(other)]
+    Unknown,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ToolSpec {
+    pub name: String,
+    pub description: String,
+    pub input_schema: Value,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum ToolChoice {
+    Auto,
+    Tool { name: String },
+}
+
+#[derive(Debug, Serialize)]
+pub struct RequestBody<'a> {
+    pub model: &'a str,
+    pub max_tokens: u32,
+    pub system: &'a str,
+    pub messages: &'a [Message],
+    pub tools: &'a [ToolSpec],
+    pub tool_choice: ToolChoice,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct ResponseBody {
+    #[serde(default)]
+    pub content: Vec<ContentBlock>,
+    #[serde(default)]
+    pub stop_reason: Option<String>,
+}